示例#1
0
int snd_seq_expand_var_event(const snd_seq_event_t *event, int count, char *buf, int in_kernel, int size_aligned)
{
	int len, newlen;
	int err;

	if ((len = get_var_len(event)) < 0)
		return len;
	newlen = len;
	if (size_aligned > 0)
		newlen = ((len + size_aligned - 1) / size_aligned) * size_aligned;
	if (count < newlen)
		return -EAGAIN;

	if (event->data.ext.len & SNDRV_SEQ_EXT_USRPTR) {
		if (! in_kernel)
			return -EINVAL;
		if (copy_from_user(buf, event->data.ext.ptr, len))
			return -EFAULT;
		return newlen;
	}
	err = snd_seq_dump_var_event(event,
				     in_kernel ? (snd_seq_dump_func_t)seq_copy_in_kernel :
				     (snd_seq_dump_func_t)seq_copy_in_user,
				     &buf);
	return err < 0 ? err : newlen;
}
int snd_seq_dump_var_event(const struct snd_seq_event *event,
			   snd_seq_dump_func_t func, void *private_data)
{
	int len, err;
	struct snd_seq_event_cell *cell;

	if ((len = get_var_len(event)) <= 0)
		return len;

	if (event->data.ext.len & SNDRV_SEQ_EXT_USRPTR) {
		char buf[32];
		char __user *curptr = (char __force __user *)event->data.ext.ptr;
		while (len > 0) {
			int size = sizeof(buf);
			if (len < size)
				size = len;
			if (copy_from_user(buf, curptr, size))
				return -EFAULT;
			err = func(private_data, buf, size);
			if (err < 0)
				return err;
			curptr += size;
			len -= size;
		}
		return 0;
	} if (! (event->data.ext.len & SNDRV_SEQ_EXT_CHAINED)) {
		return func(private_data, event->data.ext.ptr, len);
	}

	cell = (struct snd_seq_event_cell *)event->data.ext.ptr;
	for (; len > 0 && cell; cell = cell->next) {
		int size = sizeof(struct snd_seq_event);
		if (len < size)
			size = len;
		err = func(private_data, &cell->event, size);
		if (err < 0)
			return err;
		len -= size;
	}
	return 0;
}