net: Disable LRO on devices that are forwarding
Large Receive Offload (LRO) is only appropriate for packets that are
destined for the host, and should be disabled if received packets may be
forwarded. It can also confuse the GSO on output.
Add dev_disable_lro() function which uses the appropriate ethtool ops to
disable LRO if enabled.
Add calls to dev_disable_lro() in br_add_if() and functions that enable
IPv4 and IPv6 forwarding.
Signed-off-by: Ben Hutchings <bhutchings@solarflare.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/net/ipv4/devinet.c b/net/ipv4/devinet.c
index f8c0b0a..9de2514 100644
--- a/net/ipv4/devinet.c
+++ b/net/ipv4/devinet.c
@@ -168,6 +168,8 @@
in_dev->dev = dev;
if ((in_dev->arp_parms = neigh_parms_alloc(dev, &arp_tbl)) == NULL)
goto out_kfree;
+ if (IPV4_DEVCONF(in_dev->cnf, FORWARDING))
+ dev_disable_lro(dev);
/* Reference in_dev->dev */
dev_hold(dev);
/* Account for reference dev->ip_ptr (below) */
@@ -1241,6 +1243,8 @@
read_lock(&dev_base_lock);
for_each_netdev(net, dev) {
struct in_device *in_dev;
+ if (on)
+ dev_disable_lro(dev);
rcu_read_lock();
in_dev = __in_dev_get_rcu(dev);
if (in_dev)
@@ -1248,8 +1252,6 @@
rcu_read_unlock();
}
read_unlock(&dev_base_lock);
-
- rt_cache_flush(0);
}
static int devinet_conf_proc(ctl_table *ctl, int write,
@@ -1335,10 +1337,19 @@
if (write && *valp != val) {
struct net *net = ctl->extra2;
- if (valp == &IPV4_DEVCONF_ALL(net, FORWARDING))
- inet_forward_change(net);
- else if (valp != &IPV4_DEVCONF_DFLT(net, FORWARDING))
+ if (valp != &IPV4_DEVCONF_DFLT(net, FORWARDING)) {
+ rtnl_lock();
+ if (valp == &IPV4_DEVCONF_ALL(net, FORWARDING)) {
+ inet_forward_change(net);
+ } else if (*valp) {
+ struct ipv4_devconf *cnf = ctl->extra1;
+ struct in_device *idev =
+ container_of(cnf, struct in_device, cnf);
+ dev_disable_lro(idev->dev);
+ }
+ rtnl_unlock();
rt_cache_flush(0);
+ }
}
return ret;