Re: [RFC 06/12] arp: Check all configured addresses in ARP filtering

[David Gibson <david@gibson.dropbear.id.au>]

[-- Attachment #1: Type: text/plain, Size: 1665 bytes --]

On Sun, Dec 14, 2025 at 08:54:35PM -0500, Jon Maloy wrote:
> We update ignore_arp() to check against all addresses in the addrs[]
> array, not just addrs[0]. This ensures ARP requests for any of the
> guest's configured addresses are properly ignored.
> 
> Signed-off-by: Jon Maloy <jmaloy@redhat.com>
> ---
>  arp.c | 9 ++++++---
>  1 file changed, 6 insertions(+), 3 deletions(-)
> 
> diff --git a/arp.c b/arp.c
> index 7eaf517..61c309e 100644
> --- a/arp.c
> +++ b/arp.c
> @@ -41,6 +41,8 @@
>  static bool ignore_arp(const struct ctx *c,
>  		       const struct arphdr *ah, const struct arpmsg *am)
>  {
> +	int i;
> +
>  	if (ah->ar_hrd != htons(ARPHRD_ETHER)	||
>  	    ah->ar_pro != htons(ETH_P_IP)	||
>  	    ah->ar_hln != ETH_ALEN		||
> @@ -53,9 +55,10 @@ static bool ignore_arp(const struct ctx *c,
>  	    !memcmp(am->sip, am->tip, sizeof(am->sip)))
>  		return true;
>  
> -	/* Don't resolve the guest's assigned address, either. */
> -	if (!memcmp(am->tip, &c->ip4.addrs[0].addr, sizeof(am->tip)))
> -		return true;
> +	/* Don't resolve any of the guest's assigned addresses, either */
> +	for (i = 0; i < c->ip4.addr_count; i++)
> +		if (!memcmp(am->tip, &c->ip4.addrs[i].addr, sizeof(am->tip)))
> +			return true;

Ah, right.  I think this needs to move earlier in the series,
otherwise things are broken in between allowing multiple addresses and
this change.

>  
>  	return false;
>  }
> -- 
> 2.51.1
> 

-- 
David Gibson (he or they)	| I'll have my music baroque, and my code
david AT gibson.dropbear.id.au	| minimalist, thank you, not the other way
				| around.
http://www.ozlabs.org/~dgibson

[-- Attachment #2: signature.asc --]
[-- Type: application/pgp-signature, Size: 833 bytes --]