/*********************************************************/
/*  toksvc: a framework-native token broker service      */
/*  Copyright (C) 2020  Z. Gilboa                        */
/*  Released under GPLv2 and GPLv3; see COPYING.TOKSVC.  */
/*********************************************************/

#include <psxtypes/psxtypes.h>
#include <ntapi/ntapi.h>

#include <toksvc/toksvc.h>
#include "toksvc_driver_impl.h"

static const uint32_t toks_sd_access_bits[8] = {
	0,
	NT_GENERIC_EXECUTE,
	NT_GENERIC_WRITE,
	NT_GENERIC_WRITE | NT_GENERIC_EXECUTE,
	NT_GENERIC_READ,
	NT_GENERIC_READ  | NT_GENERIC_EXECUTE ,
	NT_GENERIC_READ  | NT_GENERIC_WRITE,
	NT_GENERIC_READ  | NT_GENERIC_WRITE | NT_GENERIC_EXECUTE
};

static nt_sd * toks_fsfile_sd(
	nt_sd_common_buffer *	sd,
	uint32_t		mode)
{
	uint32_t		access_owner;
	uint32_t		access_group;
	uint32_t		access_other;
	uint32_t		access_admin;
	nt_sid *		admin_sid;

	access_owner  = (((mode & 0700) >> 6) == 7)
		? NT_GENERIC_ALL | NT_SEC_SPECIFIC_RIGHTS_ALL
		: toks_sd_access_bits[(mode & 0700) >> 6]
			| NT_SEC_STANDARD_RIGHTS_ALL;

	access_group  = toks_sd_access_bits[(mode & 0070) >> 3];
	access_group |= NT_SEC_READ_CONTROL|NT_FILE_READ_ATTRIBUTES;

	access_other  = toks_sd_access_bits[(mode & 0007) >> 0];
	access_other |= NT_SEC_READ_CONTROL|NT_FILE_READ_ATTRIBUTES;

	admin_sid    = 0;
	access_admin = access_owner;

	ntapi->acl_init_common_descriptor(
		sd,0,0,
		0,admin_sid,
		access_owner,access_group,access_other,
		access_admin,access_owner,
		0);

	return &sd->sd;
}

static int32_t toks_open(
	void **		hfile,
	void *		hat,
	const char *	arg,
	nt_sd *		sd,
	uint32_t	attr,
	uint32_t	options,
	uint32_t	disposition,
	bool		fprivate)
{
	int32_t						status;
	nt_oa						oa;
	nt_iosb						iosb;
	nt_unicode_string				path;
	nt_unicode_conversion_params_utf8_to_utf16	params = {0,0,0,0,0,0,0,0,0};
	wchar16_t					buffer[4096];
	wchar16_t *					wch;
	size_t						nbytes;
	uint32_t					access;
	nt_large_integer				alloc_size;

	/* utf-8 --> utf-16 */
	params.src		= (const unsigned char *)arg;
	params.src_size_in_bytes= ntapi->tt_string_null_offset_multibyte(arg);
	params.dst		= buffer;
	params.dst_size_in_bytes= sizeof(buffer);

	if ((status = ntapi->uc_convert_unicode_stream_utf8_to_utf16(&params)))
		return status;

	/* convenience */
	for (wch=buffer, nbytes=params.bytes_written; nbytes; ) {
		if (*wch == '/')
			*wch = '\\';

		nbytes -= sizeof(wchar16_t);
		wch++;
	}

	/* path */
	path.maxlen = 0;
	path.strlen = (uint16_t)params.bytes_written;
	path.buffer = buffer;

	/* oa */
	oa.len      = sizeof(nt_oa);
	oa.root_dir = (buffer[0]=='\\') ? 0 : hat;
	oa.obj_name = &path;
	oa.obj_attr = fprivate ? 0 : NT_OBJ_INHERIT;
	oa.sec_desc = sd;
	oa.sec_qos  = 0;

	/* alloc_size (always zero) */
	alloc_size.quad = 0;

	/* access */
	access  = NT_SEC_SYNCHRONIZE | NT_FILE_READ_ATTRIBUTES | NT_FILE_READ_DATA;
	access |= (disposition == NT_FILE_OPEN_IF) ? NT_FILE_WRITE_DATA : 0;

	/* open/create */
	return ntapi->zw_create_file(
		hfile,
		access,&oa,&iosb,&alloc_size,attr,
		NT_FILE_SHARE_READ | NT_FILE_SHARE_WRITE | NT_FILE_SHARE_DELETE,
		disposition,
		options | NT_FILE_SYNCHRONOUS_IO_ALERT,
		0,0);
}

static int32_t toks_open_volume(
	void **		hfile,
	void *		hat,
	const char *	arg,
	nt_sd *		sd,
	uint32_t	attr,
	uint32_t	options,
	uint32_t	disposition,
	bool		fprivate)
{
	int32_t   status;
	void *    hvolume = 0;
	wchar16_t drive   = arg[0];

	if ((arg[1]==':') && ((arg[2]=='\\') || (arg[2]=='/'))) {
		if ((status = ntapi->tt_get_dos_drive_root_handle(
				&hvolume,drive)))
			return status;

		hat = hvolume;
		arg = &arg[3];
	}

	status = toks_open(
		hfile,hat,arg,sd,attr,
		options,disposition,
		fprivate);

	if (hvolume)
		ntapi->zw_close(hvolume);

	return status;
}

int32_t toks_open_file(void ** hfile, void * hat, const char * arg, bool fprivate)
{
	return toks_open_volume(
		hfile,hat,arg,0,
		NT_FILE_ATTRIBUTE_NORMAL,
		NT_FILE_NON_DIRECTORY_FILE,
		NT_FILE_OPEN,
		fprivate);
}

int32_t toks_open_log_file(void ** hfile, void * hat, const char * arg, bool fprivate)
{
	int32_t                 status;
	nt_iosb                 iosb;
	nt_fsi                  fsi;
	nt_fpi                  fpi;
	nt_sd_common_buffer     sd;

	if ((status = toks_open_volume(
			hfile,hat,arg,
			toks_fsfile_sd(&sd,0644),
			NT_FILE_ATTRIBUTE_NORMAL,
			NT_FILE_NON_DIRECTORY_FILE,
			NT_FILE_OPEN_IF,
			fprivate)))
		return status;

	status = ntapi->zw_query_information_file(
		*hfile,&iosb,
		&fsi,sizeof(fsi),
		NT_FILE_STANDARD_INFORMATION);

	if (status) {
		ntapi->zw_close(*hfile);
		return status;
	}

	fpi.current_byte_offset.quad = fsi.end_of_file.quad;

	status = ntapi->zw_set_information_file(
		*hfile,&iosb,
		&fpi,sizeof(fpi),
		NT_FILE_POSITION_INFORMATION);

	if (status) {
		ntapi->zw_close(*hfile);
		return status;
	}

	return NT_STATUS_SUCCESS;
}

int32_t toks_open_dir(void ** hfile, void * hat, const char * arg, bool fprivate)
{
	return toks_open_volume(
		hfile,hat,arg,0,
		NT_FILE_ATTRIBUTE_DIRECTORY,
		NT_FILE_DIRECTORY_FILE,
		NT_FILE_OPEN,
		fprivate);
}