Re: [PATCH v9 9/9] arp/ndp: send gratuitous ARP / unsolicitated NA when MAC cache entry added

[Jon Maloy <jmaloy@redhat.com>]

On 2025-09-24 18:18, Jon Maloy wrote:
> 
> 
> On 2025-09-23 23:22, David Gibson wrote:
>> On Tue, Sep 23, 2025 at 09:13:30PM -0400, Jon Maloy wrote:

[...]

>>> --- a/fwd.c
>>> +++ b/fwd.c
>>> @@ -26,6 +26,8 @@
>>>   #include "passt.h"
>>>   #include "lineread.h"
>>>   #include "flow_table.h"
>>> +#include "arp.h"
>>> +#include "ndp.h"
>>>   /* Empheral port range: values from RFC 6335 */
>>>   static in_port_t fwd_ephemeral_min = (1 << 15) + (1 << 14);
>>> @@ -129,6 +131,15 @@ void fwd_neigh_mac_cache_alloc(const struct ctx *c,
>>>       memcpy(&e->addr, addr, sizeof(*addr));
>>>       memcpy(e->mac, mac, ETH_ALEN);
>>> +
>>> +    /* Send gratuitous ARP / unsolicited NA for the new mapping */
>>
>> AFAICT this doesn't actually implement what the commit message
>> describes - it seems to always send an ARP/NA when the neighbour table
>> is updated.

No. Check the code again.

///jon

>>
>>> +    if (inany_v4(addr)) {
>>> +        struct in_addr ip4 = *inany_v4(addr);
>