Re: [PATCHv2 net-next] rtnetlink: Honour NLM_F_ECHO flag in rtnl_{new, set, del}link

[Hangbin Liu <liuhangbin@gmail.com>]

On Mon, Sep 26, 2022 at 03:12:46PM +0800, Hangbin Liu wrote:
> +static void rtnl_link_notify(struct net_device *dev, u32 pid,
> +			     struct nlmsghdr *nlh)
> +{
> +	struct sk_buff *skb;
> +	int err = -ENOBUFS;
> +
> +	skb = nlmsg_new(if_nlmsg_size(dev, 0), GFP_KERNEL);
> +	if (!skb)
> +		goto errout;
> +
> +	err = rtnl_fill_ifinfo(skb, dev, dev_net(dev), RTM_NEWLINK, pid,
> +			       nlh->nlmsg_seq, 0, 0, 0, 0, NULL, 0, 0,
> +			       GFP_KERNEL);
> +	if (err < 0) {
> +		/* -EMSGSIZE implies BUG in if_nlmsg_size */
> +		WARN_ON(err == -EMSGSIZE);
> +		kfree_skb(skb);
> +		goto errout;
> +	}
> +
> +	rtnl_notify(skb, dev_net(dev), pid, RTM_NEWLINK, nlh, GFP_KERNEL);
> +
> +errout:
> +	if (err < 0)
> +		rtnl_set_sk_err(dev_net(dev), RTM_NEWLINK, err);
> +}
> +

Oh, I just find there is a similar helper function rtmsg_ifinfo_build_skb().
I will check if I can just update and re-use this helper.

Thanks
Hangbin