From 285727600fa3714051cda1c21f20a8a3842f3dd8 Mon Sep 17 00:00:00 2001 From: Veaceslav Falico Date: Fri, 28 Feb 2014 12:39:19 +0100 Subject: [PATCH] bonding: send arp requests even if there's no route to them MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Currently we're only sending arp requests if we have a route to the target (and, thus, can find out the source ip address). There are some use cases, however, where we don't want/need to set an ip address (or set up a specific route) for bonding to use arp monitoring *for traffic generation*. We can easily send arp probes (arp requests with src ip == 0) to generate arp broadcast responses from the target ip and use them for determining if the target is up. This, obviously, won't work with arp validation - because we don't have the ip address set and, thus, will filter out the responses. So in that case - print a warning. CC: François CACHEREUL CC: Zhenjie Chen CC: Jay Vosburgh CC: Andy Gospodarek Signed-off-by: Veaceslav Falico Signed-off-by: David S. Miller --- drivers/net/bonding/bond_main.c | 9 +++++++-- 1 file changed, 7 insertions(+), 2 deletions(-) diff --git a/drivers/net/bonding/bond_main.c b/drivers/net/bonding/bond_main.c index 12948b33451a..12861e37d526 100644 --- a/drivers/net/bonding/bond_main.c +++ b/drivers/net/bonding/bond_main.c @@ -2155,8 +2155,13 @@ static void bond_arp_send_all(struct bonding *bond, struct slave *slave) rt = ip_route_output(dev_net(bond->dev), targets[i], 0, RTO_ONLINK, 0); if (IS_ERR(rt)) { - pr_debug("%s: no route to arp_ip_target %pI4\n", - bond->dev->name, &targets[i]); + /* there's no route to target - try to send arp + * probe to generate any traffic (arp_validate=0) + */ + if (bond->params.arp_validate && net_ratelimit()) + pr_warn("%s: no route to arp_ip_target %pI4 and arp_validate is set\n", + bond->dev->name, &targets[i]); + bond_arp_send(slave->dev, ARPOP_REQUEST, targets[i], 0, 0); continue; }