nativelibc/posix-io/dirent.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.
*/

#define _DIRENT_IMPLEMENTATION
#include <dirent.h>
#include <unistd.h>
#include <windows.h>
#include <nt.h>
#include <errno.h>
#include <fcntl.h>
#include <wchar.h>
#include <stdlib.h>
#include <string.h>
#include <stdio.h>
#include <ntstatus.h>

static unsigned char file_attribute_to_dirent_type(unsigned long int attrib) {
	if(attrib & FILE_ATTRIBUTE_DIRECTORY) return DT_DIR;
	return DT_REG;
}

static unsigned char object_type_name_to_dirent_type(const UNICODE_STRING *type_name) {
	//printf("nativelibc debug: object_type_name_to_dirent_type: type_name: ");
	//NtDisplayString((UNICODE_STRING *)type_name);
	//putchar('\n');
	if(wcscmp(type_name->Buffer, L"Device") == 0) return DT_CHR;		// XXX
	if(wcscmp(type_name->Buffer, L"Directory") == 0) return DT_DIR;
	if(wcscmp(type_name->Buffer, L"File") == 0) return DT_REG;
	if(wcscmp(type_name->Buffer, L"SymbolicLink") == 0) return DT_LNK;
	return DT_UNKNOWN;
}

DIR *opendir(const char *name) {
	//printf("function: opendir(%p<%s>)\n", name, name);
	DIR *r = malloc(sizeof(DIR));
	if(!r) return NULL;
	int fd = open(name, O_RDONLY | O_DIRECTORY);
	if(fd == -1) {
		free(r);
		return NULL;
	}
	r->handle = (void *)fd;

	size_t oti_size = sizeof(OBJECT_TYPE_INFORMATION) + 64;
	OBJECT_TYPE_INFORMATION *oti = malloc(oti_size);
	if(!oti) {
		free(r);
		return NULL;
	}
	long int status = NtQueryObject(r->handle, ObjectTypeInformation, oti, oti_size, NULL);
	//printf("nativelibc debug: opendir: status = 0x%lx\n", status);
	if(status < 0) {
		free(r);
		__set_errno_from_ntstatus(status);
		return NULL;
	}
	if(wcscmp(oti->TypeName.Buffer, L"Directory") == 0) r->type = _DIRTYPE_OBJECT;
	else if(wcscmp(oti->TypeName.Buffer, L"File") == 0) r->type = _DIRTYPE_FILE;
	else {
		// This is not expected, because the open function is already open a directory successfully
		puts("nativelibc warning: opendir: unexpected object type!");
		free(oti);
		free(r);
		errno = ENOTDIR;
		return NULL;
	}
	free(oti);

	r->context = 0;
	r->dir.d_ino = 0;
	r->dir.d_reclen = sizeof r->dir;
	*r->dir.d_name = 0;
	return r;
}

struct dirent *readdir(DIR *dirp) {
	//printf("function: readdir(%p)\n", dirp);
	if(!dirp) {
		errno = EBADF;
		return NULL;
	}

	if(dirp->type == _DIRTYPE_OBJECT) {
		size_t odi_size = sizeof(OBJECT_DIRECTORY_INFORMATION) + 512;
		OBJECT_DIRECTORY_INFORMATION *odi = malloc(odi_size);
		if(!odi) {
			errno = ENOMEM;
			return NULL;
		}
		long int status = NtQueryDirectoryObject(dirp->handle, odi, odi_size, 1, 0, &dirp->context, NULL);
		//printf("nativelibc debug: readdir: status = 0x%lx\n", status);
		if(status == STATUS_NO_MORE_ENTRIES) {
			free(odi);
			return NULL;
		}
		if(status < 0) {
			free(odi);
			__set_errno_from_ntstatus(status);
			return NULL;
		}
		size_t len = odi->Name.MaximumLength;
		if(len > 255) {
			dirp->dir.d_name[255] = 0;
			len = 255;
		}
		wcstombs(dirp->dir.d_name, odi->Name.Buffer, len);
		dirp->dir.d_type = object_type_name_to_dirent_type(&odi->TypeName);
		free(odi);
	} else if(dirp->type == _DIRTYPE_FILE) {
		IO_STATUS_BLOCK io_status;
		//size_t fifdi_size = sizeof(FILE_ID_FULL_DIRECTORY_INFORMATION) + 512;
		//FILE_ID_FULL_DIRECTORY_INFORMATION *fifdi = malloc(fifdi_size);
		size_t fdi_size = sizeof(FILE_DIRECTORY_INFORMATION) + 512;
		FILE_DIRECTORY_INFORMATION *fdi = malloc(fdi_size);
		if(!fdi) {
			errno = ENOMEM;
			return NULL;
		}
		long int status = NtQueryDirectoryFile(dirp->handle, NULL, NULL, NULL, &io_status, fdi, fdi_size, FileDirectoryInformation, 1, NULL, dirp->context == 0);
		//printf("nativelibc debug: readdir: status = 0x%lx\n", status);
		if(status == STATUS_NO_MORE_ENTRIES) {
			free(fdi);
			return NULL;
		}
		if(status < 0) {
			free(fdi);
			__set_errno_from_ntstatus(status);
			return NULL;
		}
		dirp->context++;
		size_t len = fdi->FileNameLength;
		if(len > 255) len = 255;
		fdi->FileName[len / sizeof(wchar_t)] = 0;
		wcstombs(dirp->dir.d_name, fdi->FileName, len);
		//dirp->dir.d_name[cc < 0 ? 0 : len] = 0;
		dirp->dir.d_type = file_attribute_to_dirent_type(fdi->FileAttributes);
		//dirp->dir.d_ino = fifdi->FileId.QuadPart;
		free(fdi);
	} else {
		errno = EBADF;
		return NULL;
	}
	//dirp->index++;
	return &dirp->dir;
}

int closedir(DIR *dirp) {
	//printf("function: closedir(%p)\n", dirp);
	if(!dirp) {
		errno = EBADF;
		return -1;
	}

	NtClose(dirp->handle);
	//free(dirp->data);
	return 0;
}

void rewinddir(DIR *dirp) {
	if(!dirp) return;
	dirp->context = 0;
}

long int telldir(DIR *dirp) {
	if(!dirp) {
		errno = EBADF;
		return -1;
	}
	return dirp->context;
}

void seekdir(DIR *dirp, long int offset) {
	if(!dirp) return;
	if(offset < 0) return;
	switch(dirp->type) {
		case _DIRTYPE_OBJECT:
			dirp->context = offset;
			return;
		case _DIRTYPE_FILE:
			rewinddir(dirp);
			while(dirp->context < offset && readdir(dirp));
			return;
	}
}