/********************************************************/
/*  ntapi: Native API core library                      */
/*  Copyright (C) 2013--2021  SysDeer Technologies, LLC */
/*  Released under GPLv2 and GPLv3; see COPYING.NTAPI.  */
/********************************************************/

#include <ntapi/ntapi.h>
#include <ntapi/nt_file.h>
#include <ntapi/nt_fsctl.h>
#include <ntapi/nt_mount.h>
#include <ntapi/nt_stat.h>
#include "ntapi_impl.h"

int32_t __stdcall __ntapi_tt_stat(
	__in	void *			hfile,
	__out	nt_stat *		stat,
	__in	uint32_t		infolen,
	__out	uintptr_t *		buffer,
	__in	uint32_t		buffer_size,
	__in	uint32_t		flags)
{
	int32_t			status;
	nt_iosb			iosb;
	nt_unicode_string *	sdev;
	nt_fai *		fai;
	wchar16_t *		wch;
	wchar16_t *		wch_mark;
	wchar16_t *		wch_cap;
	uint32_t		hash;
	uint32_t		written;

	/* validation */
	if (infolen < sizeof(*stat))
		return NT_STATUS_INFO_LENGTH_MISMATCH;

	/* init */
	__ntapi->tt_aligned_block_memset(
		stat,0,sizeof(*stat));

        stat->hfile           = hfile;
        stat->dev_name_maxlen = (uint16_t)infolen - sizeof(*stat);

	/* sigh */
	if (buffer_size >= 65536)
		buffer_size = 65535;

	/* system-unique device name */
	if ((status = __ntapi->zw_query_information_file(
			hfile,
			&iosb,
			buffer,
			buffer_size,
			NT_FILE_ALL_INFORMATION)))
		return status;

	/* copy file info minus name */
	__ntapi->tt_aligned_block_memcpy(
		(uintptr_t *)stat,
		(uintptr_t *)buffer,
		__offsetof(nt_fai,name_info));

	/* record volume-relative file name length */
	fai = (nt_fai *)buffer;
	stat->file_name_length = fai->name_info.file_name_length;

	/* file system size information */
	if ((status = __ntapi->zw_query_volume_information_file(
			hfile,
			&iosb,
			&(stat->fssi),
			sizeof(stat->fssi),
			NT_FILE_FS_SIZE_INFORMATION)))
		return status;

	/* system-unique device name */
	if ((status = __ntapi->zw_query_object(
			hfile,
			NT_OBJECT_NAME_INFORMATION,
			buffer,
			buffer_size,
			&written)))
		return status;

	sdev = (nt_unicode_string *)buffer;
	wch  = sdev->buffer;

	if (sdev->strlen < __DEVICE_PATH_PREFIX_LEN)
		return NT_STATUS_NOT_SUPPORTED;

	if ((wch[0] != '\\')
			|| (wch[1] != 'D')
			|| (wch[2] != 'e')
			|| (wch[3] != 'v')
			|| (wch[4] != 'i')
			|| (wch[5] != 'c')
			|| (wch[6] != 'e')
			|| (wch[7] != '\\'))
		return NT_STATUS_NOT_SUPPORTED;

	if ((sdev->strlen >= __DEVICE_MUP_PREFIX_LEN)
			&& (wch[8]=='M')
			&& (wch[9]=='u')
			&& (wch[10]=='p')
			&& (wch[11]=='\\')) {
		hash = __DEVICE_MUP_PREFIX_HASH;
		stat->flags |= NT_STAT_MUP_DEVICE;

		wch_mark = &wch[12];
		wch      = wch_mark;

		for (; *wch!='\\'; )
			wch++;
		wch++;
	} else {
		wch_mark = &wch[8];
		wch      = wch_mark;
		hash     = __DEVICE_PATH_PREFIX_HASH;
	}

	wch_cap = sdev->buffer + (sdev->strlen / sizeof(wchar16_t));

	for (; wch<wch_cap && *wch!='\\'; )
		wch++;

	stat->obj_name_strlen = sdev->strlen;
	stat->obj_name_maxlen = stat->dev_name_maxlen;
	stat->dev_name_strlen = sizeof(uint16_t) * (uint16_t)(wch - sdev->buffer);
	stat->dev_name_hash   = __ntapi->tt_buffer_crc32(
					hash,wch_mark,
					sizeof(wchar16_t) * (wch - wch_mark));

	if (!(flags & NT_STAT_DEV_NAME_COPY))
		return NT_STATUS_SUCCESS;
	else if (stat->dev_name_maxlen < sdev->strlen)
		return NT_STATUS_BUFFER_TOO_SMALL;

	__ntapi->tt_memcpy_utf16(
		(wchar16_t *)stat->dev_name,
		(wchar16_t *)sdev->buffer,
		sdev->strlen);

	return NT_STATUS_SUCCESS;
}