Hi Jakub,
Yes to all your suggestions.
Thanks for the review.
Jeff
On 11/12/20 12:32 PM, Jakub Kicinski wrote:
> On Tue, 10 Nov 2020 12:23:05 -0500 Jeff Dike wrote:
>> Commit 58956317c8de ("neighbor: Improve garbage collection")
>> guarantees neighbour table entries a five-second lifetime. Processes
>> which make heavy use of multicast can fill the neighour table with
>> multicast addresses in five seconds. At that point, neighbour entries
>> can't be GC-ed because they aren't five seconds old yet, the kernel
>> log starts to fill up with "neighbor table overflow!" messages, and
>> sends start to fail.
>>
>> This patch allows multicast addresses to be thrown out before they've
>> lived out their five seconds. This makes room for non-multicast
>> addresses and makes messages to all addresses more reliable in these
>> circumstances.
>
> We should add
>
> Fixes: 58956317c8de ("neighbor: Improve garbage collection")
>
> right?
>
>> Signed-off-by: Jeff Dike <jd...@akamai.com>
>
>> diff --git a/net/ipv4/arp.c b/net/ipv4/arp.c
>> index 687971d83b4e..097aa8bf07ee 100644
>> --- a/net/ipv4/arp.c
>> +++ b/net/ipv4/arp.c
>> @@ -125,6 +125,7 @@ static int arp_constructor(struct neighbour *neigh);
>> static void arp_solicit(struct neighbour *neigh, struct sk_buff *skb);
>> static void arp_error_report(struct neighbour *neigh, struct sk_buff *skb);
>> static void parp_redo(struct sk_buff *skb);
>> +static int arp_is_multicast(const void *pkey);
>>
>> static const struct neigh_ops arp_generic_ops = {
>> .family = AF_INET,
>> @@ -156,6 +157,7 @@ struct neigh_table arp_tbl = {
>> .key_eq = arp_key_eq,
>> .constructor = arp_constructor,
>> .proxy_redo = parp_redo,
>> + .is_multicast = arp_is_multicast,
>
> extreme nit pick - please align the = sign using tabs like the
> surrounding code does.
>
>> .id = "arp_cache",
>> .parms = {
>> .tbl = &arp_tbl,
>> @@ -928,6 +930,10 @@ static void parp_redo(struct sk_buff *skb)
>> arp_process(dev_net(skb->dev), NULL, skb);
>> }
>>
>> +static int arp_is_multicast(const void *pkey)
>> +{
>> + return ipv4_is_multicast(*((__be32 *)pkey));
>> +}
>>
>> /*
>> * Receive an arp request from the device layer.
>> diff --git a/net/ipv6/ndisc.c b/net/ipv6/ndisc.c
>> index 27f29b957ee7..67457cfadcd2 100644
>> --- a/net/ipv6/ndisc.c
>> +++ b/net/ipv6/ndisc.c
>> @@ -81,6 +81,7 @@ static void ndisc_error_report(struct neighbour *neigh,
>> struct sk_buff *skb);
>> static int pndisc_constructor(struct pneigh_entry *n);
>> static void pndisc_destructor(struct pneigh_entry *n);
>> static void pndisc_redo(struct sk_buff *skb);
>> +static int ndisc_is_multicast(const void *pkey);
>>
>> static const struct neigh_ops ndisc_generic_ops = {
>> .family = AF_INET6,
>> @@ -115,6 +116,7 @@ struct neigh_table nd_tbl = {
>> .pconstructor = pndisc_constructor,
>> .pdestructor = pndisc_destructor,
>> .proxy_redo = pndisc_redo,
>> + .is_multicast = ndisc_is_multicast,
>
> looks like the character after = is expected to be a tab, for better or
> worse
>
>> .allow_add = ndisc_allow_add,
>> .id = "ndisc_cache",
>> .parms = {
>> @@ -1706,6 +1708,11 @@ static void pndisc_redo(struct sk_buff *skb)
>> kfree_skb(skb);
>> }
>>
>> +static int ndisc_is_multicast(const void *pkey)
>> +{
>> + return ipv6_addr_is_multicast((struct in6_addr *)pkey);
>> +}
>> +
>> static bool ndisc_suppress_frag_ndisc(struct sk_buff *skb)
>> {
>> struct inet6_dev *idev = __in6_dev_get(skb->dev);
>
