nativelibc/statfs.c

/*	A part of the Native C Library for Windows NT
	Copyright 2007-2015 PC GO Ld.

	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; either version 2 of the License, or (at your option) any later version.

	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.
*/

#include <sys/statfs.h>
#include <windows.h>
#include <nt.h>
#include <errno.h>
#include <unistd.h>
#include <fcntl.h>
#include <stdlib.h>
#include <ntstatus.h>
#include <pathname.h>

//#include <stdio.h>

static int truncate_to_device(UNICODE_STRING *path) {
	void *handle;
	size_t len = path->Length / sizeof(wchar_t) - 1;
	if(len && path->Buffer[len] == '\\') path->Buffer[len--] = 0;
	//while(path->Buffer[--len] != L'/') if(!len) return -1;
	do {
		if(!len-- || !len) return -1;
	} while(path->Buffer[len] != L'\\');
	UNICODE_STRING up_path = { len * sizeof(wchar_t), (len + 1) * sizeof(wchar_t), malloc((len + 1) * sizeof(wchar_t)) };
	if(!up_path.Buffer) return -1;
	memcpy(up_path.Buffer, path->Buffer, len * sizeof(wchar_t));
	up_path.Buffer[len] = 0;
	OBJECT_ATTRIBUTES object_attrib = { sizeof(OBJECT_ATTRIBUTES), NULL, &up_path, 0, NULL, NULL };
	long int status = NtOpenDirectoryObject(&handle, DIRECTORY_QUERY, &object_attrib);
	free(up_path.Buffer);
	if(status == STATUS_OBJECT_TYPE_MISMATCH) {
		path->Length = len * sizeof(wchar_t);
		path->MaximumLength = (len + 1) * sizeof(wchar_t);
		path->Buffer[len] = 0;
		return truncate_to_device(path);
	}
	if(status < 0) return -1;
	NtClose(handle);
	return 0;
}

int fstatfs(int fd, struct statfs *buffer) {
	if(!buffer) {
		errno = EFAULT;
		return -1;
	}

	IO_STATUS_BLOCK io_status;
	//FILE_FS_SIZE_INFORMATION ffssi;
	FILE_FS_FULL_SIZE_INFORMATION ffsfsi;
	//long int status = NtQueryVolumeInformationFile((void *)fd, &io_status, &ffssi, sizeof ffssi, FileFsSizeInformation);
	//printf("nativelibc debug: fstatfs: status = 0x%lx\n", status);
	long int status = NtQueryVolumeInformationFile((void *)fd, &io_status, &ffsfsi, sizeof ffsfsi, FileFsFullSizeInformation);
	if(status < 0) {
		if(status != STATUS_OBJECT_TYPE_MISMATCH) {
			__set_errno_from_ntstatus(status);
			return -1;
		}
		buffer->f_bsize = 0;
		buffer->f_blocks = 0;
		buffer->f_bfree = 0;
		buffer->f_bavail = 0;
	} else {
		//printf("nativelibc debug: ActualAvailableAllocationUnits = %lld, CallerAvailableAllocationUnits = %lld\n", ffsfsi.ActualAvailableAllocationUnits.QuadPart, ffsfsi.CallerAvailableAllocationUnits.QuadPart);
		buffer->f_bsize = ffsfsi.BytesPerSector;
		buffer->f_blocks = ffsfsi.TotalAllocationUnits.QuadPart * ffsfsi.SectorsPerAllocationUnit;
		buffer->f_bfree = ffsfsi.ActualAvailableAllocationUnits.QuadPart * ffsfsi.SectorsPerAllocationUnit;
		buffer->f_bavail = ffsfsi.CallerAvailableAllocationUnits.QuadPart * ffsfsi.SectorsPerAllocationUnit;
	}

	size_t oni_size = sizeof(OBJECT_NAME_INFORMATION) + MNAMELEN * 2;
	OBJECT_NAME_INFORMATION *oni = malloc(oni_size);
	if(!oni) return -1;
	status = NtQueryObject((void *)fd, ObjectNameInformation, oni, oni_size, NULL);
	//printf("nativelibc debug: fstatfs: status = 0x%lx\n", status);
	if(status < 0) *buffer->f_mntfromname = 0;
	else {
		if(truncate_to_device(&oni->Name) < 0) strcpy(buffer->f_mntfromname, "obfs");
		else {
			PATHNAME_NT2UNIX_UTF16_STRUCT(oni->Name);
			if((int)wcstombs(buffer->f_mntfromname, oni->Name.Buffer, oni->Name.MaximumLength) < 0) {
				*buffer->f_mntfromname = 0;
			}
		}
	}
	free(oni);

	return 0;
}

int statfs(const char *path, struct statfs *buffer) {
	if(!path || !buffer) {
		errno = EFAULT;
		return -1;
	}
	if(!*path) {
		errno = ENOENT;
		return -1;
	}

	int fd = open(path, O_RDONLY);
	if(fd == -1) return -1;

	int r = fstatfs(fd, buffer);
	if(r < 0) return -1;
	int e = errno;
	if(close(fd) < 0) return -1;
	errno = e;
	return 0;
}