nativelibc/link.c

#include <windows.h>
#include <nt.h>
//#include <errno.h>
#include <pathname.h>

int link(const char *oldpath, const char *newpath) {
	void *handle;
	IO_STATUS_BLOCK io_status;
	unsigned long int file_share = FILE_SHARE_READ | FILE_SHARE_WRITE | FILE_SHARE_DELETE;
	unsigned long int options = FILE_FLAG_OPEN_REPARSE_POINT | FILE_SYNCHRONOUS_IO_NONALERT | FILE_OPEN_FOR_BACKUP_INTENT;
	UNICODE_STRING old_path;
	UNICODE_STRING new_path;
	RtlCreateUnicodeStringFromAsciiz(&old_path, oldpath);
	RtlCreateUnicodeStringFromAsciiz(&new_path, newpath);
	PATHNAME_UNIX2NT_UTF16_STRUCT(old_path);
	PATHNAME_UNIX2NT_UTF16_STRUCT(new_path);
	OBJECT_ATTRIBUTES old_object = { sizeof(OBJECT_ATTRIBUTES), NULL, &old_path, 0, NULL, NULL };
	long int status = NtOpenFile(&handle, DELETE | SYNCHRONIZE, &old_object, &io_status, file_share, options);
	RtlFreeUnicodeString(&old_path);
	//printf("nativelibc debug: status = 0x%lx\n",status);
	//if(ntstatus_to_errno(status)) goto failed;
	if(status < 0) goto failed;			// TODO: implemente the errno

	FILE_LINK_INFORMATION *new_link = malloc(sizeof(FILE_LINK_INFORMATION) + new_path.MaximumLength);
	if(!new_link) {
		NtClose(handle);
		//errno = ENOMEM;			// TODO: implemente the errno
		//return -1;
		goto failed;
	}
	memcpy(new_link->FileName, new_path.Buffer, new_path.MaximumLength);
	new_link->ReplaceIfExists = 0;
	new_link->RootDirectory = NULL;
	new_link->FileNameLength = new_path.Length;
	status = NtSetInformationFile(handle, &io_status, new_link, sizeof(FILE_LINK_INFORMATION) + new_path.MaximumLength, FileLinkInformation);
	//printf("nativelibc debug: status = 0x%lx\n", status);
	RtlFreeUnicodeString(&new_path);
	free(new_link);
	NtClose(handle);
	//return ntstatus_to_errno(status) ? -1 : 0;
	return status < 0 ? -1 : 0;			// TODO: implemente the errno

failed:
	RtlFreeUnicodeString(&new_path);
	return -1;
}