/* $Id$
 * User options handling code of libcaptive
 * Copyright (C) 2003 Jan Kratochvil <project-captive@jankratochvil.net>
 * 
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; exactly version 2 of June 1991 is required
 * 
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 * 
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
 */


#include "config.h"

#include "captive/options.h"	/* self */
#include <glib/gmessages.h>
#include "captive/macros.h"
#include <glib/gstrfuncs.h>
#include <stdlib.h>
#include "captive/rtl-file.h"
#include <sys/types.h>
#include <sys/stat.h>
#include <fcntl.h>
#include <sys/mman.h>
#include <openssl/md5.h>
#include <openssl/bn.h>
#include <openssl/crypto.h>
#include <ctype.h>


static void module_check_captivemodid(struct captive_options_module *options_module,const gchar *pathname_utf8)
{
#ifdef HAVE_LIBXML_XMLREADER_H
	if (!captive_options->captivemodid) {
		if (!captive_options->load_untested)
			g_error(_(
					"You do not have loaded any .captivemodid.xml database using: --modid-path\n"
					"Unable to check MS-Windows module file validity. You should load the database first.\n"
					"You may also force loading of the module although it may not be tested: --load-untested"));
		g_message(_("Loading possibly INCOMPATIBLE module as no database is present. Forced by: --load-untested: %s"),
				pathname_utf8);
		return;
		}
	if (captive_captivemodid_module_md5_lookup(captive_options->captivemodid,options_module->u.pe32.md5))
		return;
	if (!captive_options->load_untested)
		g_error(_(
				"Attempted to load UNTESTED and possibly INCOMPATIBLE module: %s\n"
				"You should get more recent identifications database: %s\n"
				"Otherwise you may also force the loading by the option: --load-untested"),
				pathname_utf8,captive_captivemodid_get_pathname_loaded(captive_options->captivemodid));
	g_message(_(
			"Loading UNTESTED and possibly INCOMPATIBLE module: %s\n"
			"Although forced by --load-untested you really should get more recent modid database: %s\n"),
			pathname_utf8,captive_captivemodid_get_pathname_loaded(captive_options->captivemodid));
#endif /* HAVE_LIBXML_XMLREADER_H */
}

gboolean captive_options_module_load(struct captive_options_module *options_module,const gchar *pathname_utf8)
{
const guint8 magic_mscf[]={'M','S','C','F',0,0,0,0};

	g_return_val_if_fail(options_module!=NULL,FALSE);
	g_return_val_if_fail(pathname_utf8!=NULL,FALSE);

	/* Open the Module */
	options_module->type=CAPTIVE_OPTIONS_MODULE_TYPE_PE32;
	options_module->pathname_utf8=g_strdup(pathname_utf8);
	options_module->u.pe32.mapped=TRUE;
	options_module->u.pe32.base=captive_rtl_file_mmap(
			&options_module->u.pe32.length,	/* lenp */
			pathname_utf8,	/* path */
			O_RDONLY,	/* open_flags */
			PROT_READ,	/* mmap_prot */
			MAP_SHARED);	/* mmap_flags */
	/* FIXME: convert errno instead of STATUS_INSUFFICIENT_RESOURCES */
	g_return_val_if_fail(options_module->u.pe32.base!=NULL,FALSE);

	if (options_module->u.pe32.length>=2
			&& (('M'<<8U)|('Z'<<0U))==GUINT16_FROM_BE(*(const guint16 *)options_module->u.pe32.base)) {
unsigned char md5_bin[1+128/8];	/* 128 bits==16 bytes; '1+' for leading stub to prevent shorter output of BN_bn2hex() */
BIGNUM *bignum;
char *hex,*s;

		/* already done above */
		/* Calculate MD5 sum and convert it to hex string: */
		MD5(options_module->u.pe32.base,options_module->u.pe32.length,md5_bin+1);
		md5_bin[0]=0xFF;	/* stub to prevent shorter output of BN_bn2hex() */
		bignum=BN_bin2bn(md5_bin,1+128/8,NULL);
		hex=BN_bn2hex(bignum);
		g_assert(strlen(hex)==2*(1+128/8));
		options_module->u.pe32.md5=g_strdup(hex+2);
		OPENSSL_free(hex);
		BN_free(bignum);
		/* BN_bn2hex() returns uppercased string: */
		g_assert(strlen(options_module->u.pe32.md5)==32);
		for (s=options_module->u.pe32.md5;*s;s++) {
			g_assert(isxdigit(*s));
			*s=tolower(*s);
			g_assert(isxdigit(*s));
			}
		module_check_captivemodid(options_module,pathname_utf8);
		}
	else if (options_module->u.pe32.length>=sizeof(magic_mscf)
			&& !memcmp(options_module->u.pe32.base,magic_mscf,sizeof(magic_mscf))) {
		g_error(_("Compressed cabinet file (\"*.??_\") not loadable - you must use cabextract(1) or EXPAND.EXE first: %s"),
				pathname_utf8);
		}
	else {
		captive_rtl_file_munmap(options_module->u.pe32.base);
		options_module->type=CAPTIVE_OPTIONS_MODULE_TYPE_GMODULE;
		options_module->u.gmodule.pathname=g_strdup(pathname_utf8);
		}

	return TRUE;
}


void captive_options_module_copy(struct captive_options_module *dest,const struct captive_options_module *src)
{
	g_return_if_fail(dest!=NULL);
	g_return_if_fail(src!=NULL);

	dest->pathname_utf8=g_strdup(src->pathname_utf8);

	dest->type=src->type;
	switch (src->type) {
		case CAPTIVE_OPTIONS_MODULE_TYPE_EMPTY: g_assert_not_reached();

		case CAPTIVE_OPTIONS_MODULE_TYPE_PE32:
			dest->u.pe32.base=g_memdup(src->u.pe32.base,src->u.pe32.length);
			dest->u.pe32.length=src->u.pe32.length;
			dest->u.pe32.mapped=FALSE;
			dest->u.pe32.md5=g_strdup(src->u.pe32.md5);
			break;

		case CAPTIVE_OPTIONS_MODULE_TYPE_GMODULE:
			dest->u.gmodule.pathname=g_strdup(src->u.gmodule.pathname);
			break;

		default: g_assert_not_reached();
		}
}


void captive_options_module_free(struct captive_options_module *options_module)
{
	g_return_if_fail(options_module!=NULL);

	g_free(options_module->pathname_utf8);

	switch (options_module->type) {
		case CAPTIVE_OPTIONS_MODULE_TYPE_EMPTY:
			break;

		case CAPTIVE_OPTIONS_MODULE_TYPE_PE32:
			if (options_module->u.pe32.mapped)
				captive_rtl_file_munmap(options_module->u.pe32.base);
			else
				g_free(options_module->u.pe32.base);
			g_free(options_module->u.pe32.md5);
			break;

		case CAPTIVE_OPTIONS_MODULE_TYPE_GMODULE:
			g_free(options_module->u.gmodule.pathname);
			break;

		default: g_assert_not_reached();
		}
}