nativelibc/posix-io/open.c

#include <windows.h>
#include <nt.h>
#include <fcntl.h>
#include <sys/stat.h>
#include <stdarg.h>
#include <errno.h>
#include <pathname.h>
#include <ntstatus.h>
#include <assert.h>

#include <stdio.h>		// For debug messages

int vopen(const char *pathname, int flags, va_list ap) {
	unsigned long int fileaccess;
	switch(flags & (O_RDONLY | O_WRONLY | O_RDWR)) {
		case O_RDONLY:
			fileaccess = GENERIC_READ;
			break;
		case O_WRONLY:
			fileaccess = GENERIC_WRITE;
			break;
		case O_RDWR:
			fileaccess = GENERIC_READ | GENERIC_WRITE;
			break;
		default:
			errno = EINVAL;
			return -1;
	}
	if(flags & O_APPEND) {
		if(!(fileaccess & GENERIC_WRITE)) {
			errno = EINVAL;
			return -1;
		}
		fileaccess = FILE_APPEND_DATA;
	}
	if(/*(flags & O_SYNC) || */!(flags & O_NONBLOCK)) fileaccess |= SYNCHRONIZE;

	unsigned long int file_create_disposition;
	switch(flags & (O_CREAT | O_EXCL | O_TRUNC)) {
		case 0:
		case O_EXCL:			// O_EXCL without O_CREAT: ignored
			// Open file if it exist, or fail if not
			file_create_disposition = FILE_OPEN;
			break;

		case O_CREAT:
			// Open file if it exist, or create it if not
			file_create_disposition = FILE_OPEN_IF;
			break;

		case O_CREAT | O_EXCL:
		case O_CREAT | O_TRUNC | O_EXCL:
			// Create file if it not exist, otherwise fail
			file_create_disposition = FILE_CREATE;
			break;

		case O_TRUNC:
		case O_TRUNC | O_EXCL:		// O_EXCL without O_CREAT: ignored
			// Open and truncate file if it exist, or fail if not
			file_create_disposition = FILE_OVERWRITE;
			break;

		case O_CREAT | O_TRUNC:
			// Open and truncate file if it exist, or create it if not
			file_create_disposition = FILE_OVERWRITE_IF;
			break;

		default:
			/* this can't happen ... all cases are covered */
			assert(!flags);
			return -1;
	}

	unsigned long int fileshare = FILE_SHARE_READ | FILE_SHARE_DELETE;
	unsigned long int fileattrib = 0;
	if(flags & O_CREAT) {
		int pmode = va_arg(ap, int);
		if((pmode & S_IWRITE) != S_IWRITE) fileattrib |= FILE_ATTRIBUTE_READONLY;
	}
	if(!fileattrib) fileattrib = FILE_ATTRIBUTE_NORMAL;

	unsigned long int file_create_options = 0;
	if(!(flags & O_NONBLOCK)) {
		if(flags & O_ASYNC) file_create_options |= FILE_SYNCHRONOUS_IO_ALERT;
		else file_create_options |= FILE_SYNCHRONOUS_IO_NONALERT;
	}
	if(flags & O_DIRECTORY) {
		fileaccess = SYNCHRONIZE;
		file_create_options |= FILE_DIRECTORY_FILE;
	} else file_create_options |= FILE_NON_DIRECTORY_FILE;
	if(flags & O_RANDOM) file_create_options |= FILE_RANDOM_ACCESS;
	else if(flags & O_SEQUENTIAL) file_create_options |= FILE_SEQUENTIAL_ONLY;
	if(flags & O_TEMPORARY) file_create_options |= FILE_DELETE_ON_CLOSE;
	if(flags & O_DIRECT) file_create_options |= FILE_NO_INTERMEDIATE_BUFFERING;
	if(flags & O_NOFOLLOW) file_create_options |= FILE_OPEN_REPARSE_POINT;

	int requset_dir = 0;
	UNICODE_STRING ntpathname;
	RtlCreateUnicodeStringFromAsciiz(&ntpathname, pathname);
	if(ntpathname.Buffer[ntpathname.Length / 2 - 1] == L'/') requset_dir = 1;
	PATHNAME_UNIX2NT_UTF16_STRUCT(ntpathname);
	OBJECT_ATTRIBUTES objectattrib = { sizeof(OBJECT_ATTRIBUTES), NULL, &ntpathname, OBJ_INHERIT, NULL, NULL };

	void *r;
	IO_STATUS_BLOCK io_status;
	if(flags & O_NOFOLLOW) {
		//objectattrib.Attributes |= OBJ_OPENLINK;
		long int status = NtOpenSymbolicLinkObject(&r, fileaccess & ~SYNCHRONIZE, &objectattrib);
		printf("nativelibc debug: open: status = 0x%lx\n", status);
		//if(status >= 0) return (int)r;
		if(status != STATUS_OBJECT_TYPE_MISMATCH) return ntstatus_to_errno(status) ? -1 : (int)r;
		//objectattrib.Attributes &= ~OBJ_OPENLINK;
	}
	long int status = NtCreateFile(&r, fileaccess, &objectattrib, &io_status, NULL, fileattrib, fileshare, file_create_disposition, file_create_options, NULL, 0);
	printf("nativelibc debug: open: status = 0x%lx\n", status);
	if(status == STATUS_OBJECT_NAME_INVALID && requset_dir && !(flags & O_CREAT)) {
		void *handle;
		long int status = NtCreateFile(&handle, fileaccess, &objectattrib, &io_status, NULL, 0, fileshare, FILE_OPEN, FILE_DIRECTORY_FILE, NULL, 0);
		printf("nativelibc debug: open: inner status = 0x%lx\n", status);
		if(status == STATUS_NOT_A_DIRECTORY) {
			errno = ENOTDIR;
			return -1;
		}
		if(status >= 0) NtClose(handle);
	}
	return ntstatus_to_errno(status) ? -1 : (int)r;
	//return status ? -1 : (int)r;		// TODO: implemente the errno
}

int open(const char *pathname, int flags, ...) {
	va_list ap;
	va_start(ap, flags);
	int r = vopen(pathname, flags, ap);
	va_end(ap);
	return r;
}