[PATCH net-next] net: ipv6: send unsolicited NA on admin up

[PATCH net-next] net: ipv6: send unsolicited NA on admin up

[David Ahern]

ndisc_notify is the ipv6 equivalent to arp_notify. When arp_notify is
set to 1, gratuitous arp requests are sent when the device is brought up.
The same is expected when ndisc_notify is set to 1 (per ndisc_notify in
Documentation/networking/ip-sysctl.txt). The NA is not sent on NETDEV_UP
event; add it.

Fixes: 5cb04436eef6 ("ipv6: add knob to send unsolicited ND on link-layer address change")
Signed-off-by: David Ahern <dsa@cumulusnetworks.com>
---
 net/ipv6/ndisc.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/net/ipv6/ndisc.c b/net/ipv6/ndisc.c
index b5812b3f7539..b23822e64228 100644
--- a/net/ipv6/ndisc.c
+++ b/net/ipv6/ndisc.c
@@ -1748,6 +1748,8 @@ static int ndisc_netdev_event(struct notifier_block *this, unsigned long event,
 	case NETDEV_CHANGEADDR:
 		neigh_changeaddr(&nd_tbl, dev);
 		fib6_run_gc(0, net, false);
+		/* fallthrough */
+	case NETDEV_UP:
 		idev = in6_dev_get(dev);
 		if (!idev)
 			break;
-- 
2.1.4

Re: [PATCH net-next] net: ipv6: send unsolicited NA on admin up

[Hannes Frederic Sowa]

On Wed, Apr 12, 2017, at 20:49, David Ahern wrote:
> ndisc_notify is the ipv6 equivalent to arp_notify. When arp_notify is
> set to 1, gratuitous arp requests are sent when the device is brought up.
> The same is expected when ndisc_notify is set to 1 (per ndisc_notify in
> Documentation/networking/ip-sysctl.txt). The NA is not sent on NETDEV_UP
> event; add it.
> 
> Fixes: 5cb04436eef6 ("ipv6: add knob to send unsolicited ND on link-layer
> address change")
> Signed-off-by: David Ahern <dsa@cumulusnetworks.com>

Acked-by: Hannes Frederic Sowa <hannes@stressinduktion.org>

In future we might be able to make this a bit more robust when DAD is
happening at the same time.

Thanks,
Hannes

Re: [PATCH net-next] net: ipv6: send unsolicited NA on admin up

[David Ahern]

On 4/13/17 5:45 AM, Hannes Frederic Sowa wrote:
> 
> 
> On Wed, Apr 12, 2017, at 20:49, David Ahern wrote:
>> ndisc_notify is the ipv6 equivalent to arp_notify. When arp_notify is
>> set to 1, gratuitous arp requests are sent when the device is brought up.
>> The same is expected when ndisc_notify is set to 1 (per ndisc_notify in
>> Documentation/networking/ip-sysctl.txt). The NA is not sent on NETDEV_UP
>> event; add it.
>>
>> Fixes: 5cb04436eef6 ("ipv6: add knob to send unsolicited ND on link-layer
>> address change")
>> Signed-off-by: David Ahern <dsa@cumulusnetworks.com>
> 
> Acked-by: Hannes Frederic Sowa <hannes@stressinduktion.org>
> 
> In future we might be able to make this a bit more robust when DAD is
> happening at the same time.


agreed.

Re: [PATCH net-next] net: ipv6: send unsolicited NA on admin up

[David Miller]

From: David Ahern <dsa@cumulusnetworks.com>
Date: Wed, 12 Apr 2017 11:49:04 -0700

> ndisc_notify is the ipv6 equivalent to arp_notify. When arp_notify is
> set to 1, gratuitous arp requests are sent when the device is brought up.
> The same is expected when ndisc_notify is set to 1 (per ndisc_notify in
> Documentation/networking/ip-sysctl.txt). The NA is not sent on NETDEV_UP
> event; add it.
> 
> Fixes: 5cb04436eef6 ("ipv6: add knob to send unsolicited ND on link-layer address change")
> Signed-off-by: David Ahern <dsa@cumulusnetworks.com>

Applied, thanks.