Upstream commit:
Prior to 4.3, openvswitch tunnel vports (vxlan, gre and geneve) could
transmit vxlan packets of any size, constrained only by the ability to
send out the resulting packets. 4.3 introduced netdevs corresponding
to tunnel vports. These netdevs have an MTU, which limits the size of
a packet that can be successfully encapsulated. The default MTU
values are low (1500 or less), which is awkwardly small in the context
of physical networks supporting jumbo frames, and leads to a
conspicuous change in behaviour for userspace.
Instead, set the MTU on openvswitch-created netdevs to be the relevant
maximum (i.e. the maximum IP packet size minus any relevant overhead),
effectively restoring the behaviour prior to 4.3.
Signed-off-by: David Wragg <david@weave.works>
Signed-off-by: David S. Miller <davem@davemloft.net>
Upstream:
7e059158d57b ("vxlan, gre, geneve: Set a large MTU on ovs-created
tunnel devices")
Signed-off-by: Joe Stringer <joe@ovn.org>
Acked-by: Jesse Gross <jesse@kernel.org>
OVS_GREP_IFELSE([$KSRC/include/net/ip.h], [IPSKB_FRAG_PMTU],
[OVS_DEFINE([HAVE_CORRECT_MRU_HANDLING])])
+ OVS_GREP_IFELSE([$KSRC/include/net/ip_tunnels.h], [__ip_tunnel_change_mtu])
OVS_GREP_IFELSE([$KSRC/include/net/inet_frag.h], [hashfn.*const],
[OVS_DEFINE([HAVE_INET_FRAGS_CONST])])
OVS_GREP_IFELSE([$KSRC/include/net/inet_frag.h], [last_in],
return dev;
err = geneve_configure(net, dev, 0, 0, 0, 0, htons(dst_port), true);
- if (err) {
- free_netdev(dev);
- return ERR_PTR(err);
- }
+ if (err)
+ goto err;
+
+ /* openvswitch users expect packet sizes to be unrestricted,
+ * so set the largest MTU we can.
+ */
+ err = geneve_change_mtu(dev, IP_MAX_MTU);
+ if (err)
+ goto err;
+
return dev;
+
+err:
+ free_netdev(dev);
+ return ERR_PTR(err);
}
EXPORT_SYMBOL_GPL(rpl_geneve_dev_create_fb);
#define ip_tunnel_get_link_net rpl_ip_tunnel_get_link_net
struct net *rpl_ip_tunnel_get_link_net(const struct net_device *dev);
#endif /* HAVE_METADATA_DST */
+
+#ifndef HAVE___IP_TUNNEL_CHANGE_MTU
+#define __ip_tunnel_change_mtu rpl___ip_tunnel_change_mtu
+int rpl___ip_tunnel_change_mtu(struct net_device *dev, int new_mtu, bool strict);
+#endif
+
#endif /* __NET_IP_TUNNELS_H */
#endif
if (err < 0)
goto out;
+
+ /* openvswitch users expect packet sizes to be unrestricted,
+ * so set the largest MTU we can.
+ */
+ err = __ip_tunnel_change_mtu(dev, IP_MAX_MTU, false);
+ if (err)
+ goto out;
+
return dev;
out:
free_netdev(dev);
return mtu;
}
-int rpl_ip_tunnel_change_mtu(struct net_device *dev, int new_mtu)
+int rpl___ip_tunnel_change_mtu(struct net_device *dev, int new_mtu, bool strict)
{
struct ip_tunnel *tunnel = netdev_priv(dev);
int t_hlen = tunnel->hlen + sizeof(struct iphdr);
+ int max_mtu = 0xFFF8 - dev->hard_header_len - t_hlen;
- if (new_mtu < 68 ||
- new_mtu > 0xFFF8 - dev->hard_header_len - t_hlen)
+ if (new_mtu < 68)
return -EINVAL;
+
+ if (new_mtu > max_mtu) {
+ if (strict)
+ return -EINVAL;
+
+ new_mtu = max_mtu;
+ }
+
dev->mtu = new_mtu;
return 0;
}
+int rpl_ip_tunnel_change_mtu(struct net_device *dev, int new_mtu)
+{
+ return rpl___ip_tunnel_change_mtu(dev, new_mtu, true);
+}
+
static void ip_tunnel_dev_free(struct net_device *dev)
{
#ifdef HAVE_DEV_TSTATS
int err;
bool use_ipv6 = false;
__be16 default_port = vxlan->cfg.dst_port;
+ struct net_device *lowerdev = NULL;
vxlan->net = src_net;
}
if (conf->remote_ifindex) {
- struct net_device *lowerdev
- = __dev_get_by_index(src_net, conf->remote_ifindex);
-
+ lowerdev = __dev_get_by_index(src_net, conf->remote_ifindex);
dst->remote_ifindex = conf->remote_ifindex;
if (!lowerdev) {
dev->needed_headroom = ETH_HLEN + VXLAN_HEADROOM;
}
+ if (conf->mtu) {
+ err = __vxlan_change_mtu(dev, lowerdev, dst, conf->mtu, false);
+ if (err)
+ return err;
+ }
+
memcpy(&vxlan->cfg, conf, sizeof(*conf));
if (!vxlan->cfg.dst_port)
vxlan->cfg.dst_port = default_port;
struct vxlan_config conf = {
.no_share = true,
.flags = VXLAN_F_COLLECT_METADATA,
+ /* Don't restrict the packets that can be sent by MTU */
+ .mtu = IP_MAX_MTU,
};
if (!options) {