diff mbox

[RFC,next] ipv6: do not send RTM_DELADDR for tentative addresses

Message ID 20170104230101.17470-1-mahesh@bandewar.net
State Accepted, archived
Delegated to: David Miller
Headers show

Commit Message

Mahesh Bandewar Jan. 4, 2017, 11:01 p.m. UTC 
From: Mahesh Bandewar <maheshb@google.com>

RTM_NEWADDR notification is sent when IFA_F_TENTATIVE is cleared from
the address. So if the address is added and deleted before DAD probes
completes, the RTM_DELADDR will be sent for which there was no
RTM_NEWADDR causing asymmetry in notification. However if the same
logic is used while sending RTM_DELADDR notification, this asymmetry
can be avoided.

Signed-off-by: Mahesh Bandewar <maheshb@google.com>
CC: Hideaki YOSHIFUJI <yoshfuji@linux-ipv6.org>
CC: Patrick McHardy <kaber@trash.net>
CC: Hannes Frederic Sowa <hannes@stressinduktion.org>
---
 net/ipv6/addrconf.c | 7 +++++++
 1 file changed, 7 insertions(+)

Comments

David Miller Jan. 6, 2017, 8:39 p.m. UTC | #1 
From: Mahesh Bandewar <mahesh@bandewar.net>
Date: Wed,  4 Jan 2017 15:01:01 -0800

> From: Mahesh Bandewar <maheshb@google.com>
> 
> RTM_NEWADDR notification is sent when IFA_F_TENTATIVE is cleared from
> the address. So if the address is added and deleted before DAD probes
> completes, the RTM_DELADDR will be sent for which there was no
> RTM_NEWADDR causing asymmetry in notification. However if the same
> logic is used while sending RTM_DELADDR notification, this asymmetry
> can be avoided.
> 
> Signed-off-by: Mahesh Bandewar <maheshb@google.com>

This makes a lot of sense, applied, thanks!
diff mbox

Patch

diff --git a/net/ipv6/addrconf.c b/net/ipv6/addrconf.c
index c1e124bc8e1e..ac9bd5620f81 100644
--- a/net/ipv6/addrconf.c
+++ b/net/ipv6/addrconf.c
@@ -4888,6 +4888,13 @@  static void inet6_ifa_notify(int event, struct inet6_ifaddr *ifa)
 	struct net *net = dev_net(ifa->idev->dev);
 	int err = -ENOBUFS;
 
+	/* Don't send DELADDR notification for TENTATIVE address,
+	 * since NEWADDR notification is sent only after removing
+	 * TENTATIVE flag.
+	 */
+	if (ifa->flags & IFA_F_TENTATIVE && event == RTM_DELADDR)
+		return;
+
 	skb = nlmsg_new(inet6_ifaddr_msgsize(), GFP_ATOMIC);
 	if (!skb)
 		goto errout;