Re: [PATCH] can: export a safe netdev_priv wrapper for candev

[Oliver Hartkopp <socketcan@hartkopp.net>]

On 10.09.2012 16:25, Kurt Van Dijck wrote:

> can: export a safe netdev_priv wrapper for candev
> 
> In net_device notifier calls, it was impossible to determine
> if a CAN device is based on candev in a safe way.
> This patch adds such test in order to access candev storage
> from within those notifiers.
> 
> Signed-off-by: Kurt Van Dijck <kurt.van.dijck@eia.be>
> 
> diff --git a/drivers/net/can/dev.c b/drivers/net/can/dev.c
> index 963e2cc..6c1e704 100644
> --- a/drivers/net/can/dev.c
> +++ b/drivers/net/can/dev.c
> @@ -795,6 +795,18 @@ void unregister_candev(struct net_device *dev)
>  }
>  EXPORT_SYMBOL_GPL(unregister_candev);
>  
> +/*
> + * Test if a network device is a candev based device
> + * and return the can_priv* if so.
> + */
> +struct can_priv *safe_candev_priv(struct net_device *dev)
> +{
> +	if ((dev->type != ARPHRD_CAN) || (dev->rtnl_link_ops != &can_link_ops))
> +		return NULL;


Nice idea!

Acked-by: Oliver Hartkopp <socketcan@hartkopp.net>

> +
> +	return netdev_priv(dev);
> +}
> +
>  static __init int can_dev_init(void)
>  {
>  	int err;
> diff --git a/include/linux/can/dev.h b/include/linux/can/dev.h
> index 7747d9b..fb0ab65 100644
> --- a/include/linux/can/dev.h
> +++ b/include/linux/can/dev.h
> @@ -106,6 +106,9 @@ u8 can_len2dlc(u8 len);
>  struct net_device *alloc_candev(int sizeof_priv, unsigned int echo_skb_max);
>  void free_candev(struct net_device *dev);
>  
> +/* a candev safe wrapper around netdev_priv */
> +struct can_priv *safe_candev_priv(struct net_device *dev);
> +
>  int open_candev(struct net_device *dev);
>  void close_candev(struct net_device *dev);
>