Re: [PATCH v6 04/13] arp: Check all configured addresses in ARP filtering

On Sat, 21 Mar 2026 20:43:24 -0400 Jon Maloy wrote:

As a preparation for handling multiple addresses, we update ignore_arp() to check against all addresses in the unified addrs[] array using the for_each_addr() macro.

Signed-off-by: Jon Maloy Reviewed-by: David Gibson

--- v3: -Adapted to single-array changes earlier in this series v6: -Made loop in ignore_arp() a little more palatable, but not entirely as suggested by David. --- arp.c | 11 +++++++---- 1 file changed, 7 insertions(+), 4 deletions(-)

diff --git a/arp.c b/arp.c index 18ff5de..6614804 100644 --- a/arp.c +++ b/arp.c @@ -41,7 +41,8 @@ static bool ignore_arp(const struct ctx *c, const struct arphdr *ah, const struct arpmsg *am) { - const struct guest_addr *a = fwd_get_addr(c, AF_INET, 0, 0); + const struct guest_addr *a; + union inany_addr addr;

if (ah->ar_hrd != htons(ARPHRD_ETHER) || ah->ar_pro != htons(ETH_P_IP) || @@ -55,9 +56,11 @@ 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 (a && !memcmp(am->tip, inany_v4(&a->addr), sizeof(am->tip))) - return true; + /* Don't resolve any of the guest's addresses */ + inany_from_af(&addr, AF_INET, am->tip); + for_each_addr(a, c, AF_INET)

It's not really obvious that this iterates over c->addrs. I think it might be clearer to build for_each_addr() to take c->addrs instead, even if it's slightly more verbose (but it shouldn't add lines either). Nit: curly brackets around blocks with multiple lines.

+ if (inany_equals(&addr, &a->addr)) + return true;

return false; }

-- Stefano