Re: [RFC][PATCH iproute2-next 2/6] ip: Introduce get_rtnl_link_stats_rta() to get link statistics

[Stephen Hemminger <stephen@networkplumber.org>]

On Thu,  1 Feb 2018 21:40:54 +0200
Serhey Popovych <serhe.popovych@gmail.com> wrote:

> +/* Based on copy_rtnl_link_stats() from kernel at net/core/rtnetlink.c */
> +static void copy_rtnl_link_stats64(struct rtnl_link_stats64 *a,
> +				   const struct rtnl_link_stats *b)
> +{
> +	a->rx_packets = b->rx_packets;
> +	a->tx_packets = b->tx_packets;
> +	a->rx_bytes = b->rx_bytes;
> +	a->tx_bytes = b->tx_bytes;
> +	a->rx_errors = b->rx_errors;
> +	a->tx_errors = b->tx_errors;
> +	a->rx_dropped = b->rx_dropped;
> +	a->tx_dropped = b->tx_dropped;
> +
> +	a->multicast = b->multicast;
> +	a->collisions = b->collisions;
> +
> +	a->rx_length_errors = b->rx_length_errors;
> +	a->rx_over_errors = b->rx_over_errors;
> +	a->rx_crc_errors = b->rx_crc_errors;
> +	a->rx_frame_errors = b->rx_frame_errors;
> +	a->rx_fifo_errors = b->rx_fifo_errors;
> +	a->rx_missed_errors = b->rx_missed_errors;
> +
> +	a->tx_aborted_errors = b->tx_aborted_errors;
> +	a->tx_carrier_errors = b->tx_carrier_errors;
> +	a->tx_fifo_errors = b->tx_fifo_errors;
> +	a->tx_heartbeat_errors = b->tx_heartbeat_errors;
> +	a->tx_window_errors = b->tx_window_errors;
> +
> +	a->rx_compressed = b->rx_compressed;
> +	a->tx_compressed = b->tx_compressed;
> +
> +	a->rx_nohandler = b->rx_nohandler;
> +}

You could treat the two structures as arrays since all values are same size.
This avoids any possible skipping of values.