Re: [PATCH] net: Fix detection for IPv4 duplicate address.

[David Miller]

From: Dongxu Liu <liudongxu3@xxxxxxxxxx>
Date: Tue, 20 Aug 2019 23:19:05 +0800

> @@ -800,8 +800,11 @@ static int arp_process(struct net *net, struct sock *sk, struct sk_buff *skb)
>  			    iptunnel_metadata_reply(skb_metadata_dst(skb),
>  						    GFP_ATOMIC);
>  
> -	/* Special case: IPv4 duplicate address detection packet (RFC2131) */
> -	if (sip == 0) {
> +/* Special case: IPv4 duplicate address detection packet (RFC2131).
> + * Linux usually sends zero to detect duplication, and windows may
> + * send a same ip (not zero, sip equal to tip) to do this detection.
> + */
> +	if (sip == 0 || sip == tip) {

Regardless of whether this is a valid change or not, you've unindented the
comment which is completely inappropriate.