This is a note to let you know that I've just added the patch titled
arp_notify: unconditionally send gratuitous ARP for NETDEV_NOTIFY_PEERS.
to the 2.6.32-longterm tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/longterm/longterm-queue-2.6.32.git;a=summary
The filename of the patch is:
arp_notify-unconditionally-send-gratuitous-arp-for-netdev_notify_peers.patch
and it can be found in the queue-2.6.32 subdirectory.
If you, or anyone else, feels it should not be added to the 2.6.32 longterm
tree,
please let <[email protected]> know about it.
>From d11327ad6695db8117c78d70611e71102ceec2ac Mon Sep 17 00:00:00 2001
From: Ian Campbell <[email protected]>
Date: Fri, 11 Feb 2011 07:44:16 +0000
Subject: arp_notify: unconditionally send gratuitous ARP for
NETDEV_NOTIFY_PEERS.
From: Ian Campbell <[email protected]>
commit d11327ad6695db8117c78d70611e71102ceec2ac upstream.
NETDEV_NOTIFY_PEER is an explicit request by the driver to send a link
notification while NETDEV_UP/NETDEV_CHANGEADDR generate link
notifications as a sort of side effect.
In the later cases the sysctl option is present because link
notification events can have undesired effects e.g. if the link is
flapping. I don't think this applies in the case of an explicit
request from a driver.
This patch makes NETDEV_NOTIFY_PEER unconditional, if preferred we
could add a new sysctl for this case which defaults to on.
This change causes Xen post-migration ARP notifications (which cause
switches to relearn their MAC tables etc) to be sent by default.
Signed-off-by: Ian Campbell <[email protected]>
Signed-off-by: David S. Miller <[email protected]>
[reported to solve hyperv live migration problem - gkh]
Cc: Haiyang Zhang <[email protected]>
Cc: Mike Surcouf <[email protected]>
Cc: Hank Janssen <[email protected]>
Signed-off-by: Greg Kroah-Hartman <[email protected]>
---
net/ipv4/devinet.c | 30 ++++++++++++++++++++----------
1 file changed, 20 insertions(+), 10 deletions(-)
--- a/net/ipv4/devinet.c
+++ b/net/ipv4/devinet.c
@@ -1025,6 +1025,21 @@ static inline bool inetdev_valid_mtu(uns
return mtu >= 68;
}
+static void inetdev_send_gratuitous_arp(struct net_device *dev,
+ struct in_device *in_dev)
+
+{
+ struct in_ifaddr *ifa = in_dev->ifa_list;
+
+ if (!ifa)
+ return;
+
+ arp_send(ARPOP_REQUEST, ETH_P_ARP,
+ ifa->ifa_address, dev,
+ ifa->ifa_address, NULL,
+ dev->dev_addr, NULL);
+}
+
/* Called only under RTNL semaphore */
static int inetdev_event(struct notifier_block *this, unsigned long event,
@@ -1076,18 +1091,13 @@ static int inetdev_event(struct notifier
}
ip_mc_up(in_dev);
/* fall through */
- case NETDEV_NOTIFY_PEERS:
case NETDEV_CHANGEADDR:
+ if (!IN_DEV_ARP_NOTIFY(in_dev))
+ break;
+ /* fall through */
+ case NETDEV_NOTIFY_PEERS:
/* Send gratuitous ARP to notify of link change */
- if (IN_DEV_ARP_NOTIFY(in_dev)) {
- struct in_ifaddr *ifa = in_dev->ifa_list;
-
- if (ifa)
- arp_send(ARPOP_REQUEST, ETH_P_ARP,
- ifa->ifa_address, dev,
- ifa->ifa_address, NULL,
- dev->dev_addr, NULL);
- }
+ inetdev_send_gratuitous_arp(dev, in_dev);
break;
case NETDEV_DOWN:
ip_mc_down(in_dev);
Patches currently in longterm-queue-2.6.32 which might be from
[email protected] are
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