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| author | Ian Campbell <Ian.Campbell@citrix.com> | 2011-02-11 07:44:16 +0000 |
|---|---|---|
| committer | David S. Miller <davem@davemloft.net> | 2011-02-14 17:47:15 -0800 |
| commit | d11327ad6695db8117c78d70611e71102ceec2ac (patch) | |
| tree | 02d76a5825c357d0383268d9502c886abc8c9987 /net | |
| parent | 0550769bb7f364fb9aeeb9412229fb7790ee79c4 (diff) | |
| download | linux-d11327ad6695db8117c78d70611e71102ceec2ac.tar.gz linux-d11327ad6695db8117c78d70611e71102ceec2ac.tar.bz2 linux-d11327ad6695db8117c78d70611e71102ceec2ac.zip | |
arp_notify: unconditionally send gratuitous ARP for NETDEV_NOTIFY_PEERS.
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 <ian.campbell@citrix.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'net')
| -rw-r--r-- | net/ipv4/devinet.c | 30 |
1 files changed, 20 insertions, 10 deletions
diff --git a/net/ipv4/devinet.c b/net/ipv4/devinet.c index 748cb5b337bd..df4616fce929 100644 --- a/net/ipv4/devinet.c +++ b/net/ipv4/devinet.c @@ -1030,6 +1030,21 @@ static inline bool inetdev_valid_mtu(unsigned mtu) 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, @@ -1082,18 +1097,13 @@ static int inetdev_event(struct notifier_block *this, unsigned long event, } 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); |