diff --git a/drivers/net/geneve.c b/drivers/net/geneve.c
index 0b14ac3b8d1189081967aad8bcbbfce30016aeea..028e3873c3107960c55f0bcff71d860fac0cad6e 100644
--- a/drivers/net/geneve.c
+++ b/drivers/net/geneve.c
@@ -1039,6 +1039,17 @@ static netdev_tx_t geneve_xmit(struct sk_buff *skb, struct net_device *dev)
return geneve_xmit_skb(skb, dev, info);
}
+static int geneve_change_mtu(struct net_device *dev, int new_mtu)
+{
+ /* GENEVE overhead is not fixed, so we can't enforce a more
+ * precise max MTU.
+ */
+ if (new_mtu < 68 || new_mtu > IP_MAX_MTU)
+ return -EINVAL;
+ dev->mtu = new_mtu;
+ return 0;
+}
+
static int geneve_fill_metadata_dst(struct net_device *dev, struct sk_buff *skb)
{
struct ip_tunnel_info *info = skb_tunnel_info(skb);
@@ -1083,7 +1094,7 @@ static const struct net_device_ops geneve_netdev_ops = {
.ndo_stop = geneve_stop,
.ndo_start_xmit = geneve_xmit,
.ndo_get_stats64 = ip_tunnel_get_stats64,
- .ndo_change_mtu = eth_change_mtu,
+ .ndo_change_mtu = geneve_change_mtu,
.ndo_validate_addr = eth_validate_addr,
.ndo_set_mac_address = eth_mac_addr,
.ndo_fill_metadata_dst = geneve_fill_metadata_dst,
@@ -1442,11 +1453,21 @@ struct net_device *geneve_dev_create_fb(struct net *net, const char *name,
err = geneve_configure(net, dev, &geneve_remote_unspec,
0, 0, 0, htons(dst_port), true, 0);
- 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(geneve_dev_create_fb);
diff --git a/drivers/net/vxlan.c b/drivers/net/vxlan.c
index 65439188c5829e1cce0464e6c34be1c8bb5c18c3..a31cd954b308fcf9792df88ec4d1d06842a3b1a1 100644
--- a/drivers/net/vxlan.c
+++ b/drivers/net/vxlan.c
@@ -2367,29 +2367,43 @@ static void vxlan_set_multicast_list(struct net_device *dev)
{
}
-static int vxlan_change_mtu(struct net_device *dev, int new_mtu)
+static int __vxlan_change_mtu(struct net_device *dev,
+ struct net_device *lowerdev,
+ struct vxlan_rdst *dst, int new_mtu, bool strict)
{
- struct vxlan_dev *vxlan = netdev_priv(dev);
- struct vxlan_rdst *dst = &vxlan->default_dst;
- struct net_device *lowerdev;
- int max_mtu;
+ int max_mtu = IP_MAX_MTU;
- lowerdev = __dev_get_by_index(vxlan->net, dst->remote_ifindex);
- if (lowerdev == NULL)
- return eth_change_mtu(dev, new_mtu);
+ if (lowerdev)
+ max_mtu = lowerdev->mtu;
if (dst->remote_ip.sa.sa_family == AF_INET6)
- max_mtu = lowerdev->mtu - VXLAN6_HEADROOM;
+ max_mtu -= VXLAN6_HEADROOM;
else
- max_mtu = lowerdev->mtu - VXLAN_HEADROOM;
+ max_mtu -= VXLAN_HEADROOM;
- if (new_mtu < 68 || new_mtu > max_mtu)
+ 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;
}
+static int vxlan_change_mtu(struct net_device *dev, int new_mtu)
+{
+ struct vxlan_dev *vxlan = netdev_priv(dev);
+ struct vxlan_rdst *dst = &vxlan->default_dst;
+ struct net_device *lowerdev = __dev_get_by_index(vxlan->net,
+ dst->remote_ifindex);
+ return __vxlan_change_mtu(dev, lowerdev, dst, new_mtu, true);
+}
+
static int egress_ipv4_tun_info(struct net_device *dev, struct sk_buff *skb,
struct ip_tunnel_info *info,
__be16 sport, __be16 dport)
@@ -2765,6 +2779,7 @@ static int vxlan_dev_configure(struct net *src_net, struct net_device *dev,
int err;
bool use_ipv6 = false;
__be16 default_port = vxlan->cfg.dst_port;
+ struct net_device *lowerdev = NULL;
vxlan->net = src_net;
@@ -2785,9 +2800,7 @@ static int vxlan_dev_configure(struct net *src_net, struct net_device *dev,
}
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) {
@@ -2811,6 +2824,12 @@ static int vxlan_dev_configure(struct net *src_net, struct net_device *dev,
needed_headroom = lowerdev->hard_header_len;
}
+ if (conf->mtu) {
+ err = __vxlan_change_mtu(dev, lowerdev, dst, conf->mtu, false);
+ if (err)
+ return err;
+ }
+
if (use_ipv6 || conf->flags & VXLAN_F_COLLECT_METADATA)
needed_headroom += VXLAN6_HEADROOM;
else
diff --git a/include/net/ip_tunnels.h b/include/net/ip_tunnels.h
index 6db96ea0144f0445c4e52c51cddcc3d25d60ccdd..dda9abf6b89c14afddf71562c763bdd6bb7d85c3 100644
--- a/include/net/ip_tunnels.h
+++ b/include/net/ip_tunnels.h
@@ -230,6 +230,7 @@ void ip_tunnel_xmit(struct sk_buff *skb, struct net_device *dev,
int ip_tunnel_ioctl(struct net_device *dev, struct ip_tunnel_parm *p, int cmd);
int ip_tunnel_encap(struct sk_buff *skb, struct ip_tunnel *t,
u8 *protocol, struct flowi4 *fl4);
+int __ip_tunnel_change_mtu(struct net_device *dev, int new_mtu, bool strict);
int ip_tunnel_change_mtu(struct net_device *dev, int new_mtu);
struct rtnl_link_stats64 *ip_tunnel_get_stats64(struct net_device *dev,
diff --git a/net/ipv4/ip_gre.c b/net/ipv4/ip_gre.c
index 7c51c4e1661f9aafc63829cf58b3b5ec28ed859e..56fdf4e0dce4ef4cb88e34096b4d06cae7de41c5 100644
--- a/net/ipv4/ip_gre.c
+++ b/net/ipv4/ip_gre.c
@@ -1240,6 +1240,14 @@ struct net_device *gretap_fb_dev_create(struct net *net, const char *name,
err = ipgre_newlink(net, dev, tb, NULL);
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);
diff --git a/net/ipv4/ip_tunnel.c b/net/ipv4/ip_tunnel.c
index c7bd72e9b544848d10a490b010e0a30c4d5e4c21..89e8861e05fcb1d371c371c1784b89499b69d9df 100644
--- a/net/ipv4/ip_tunnel.c
+++ b/net/ipv4/ip_tunnel.c
@@ -943,17 +943,31 @@ int ip_tunnel_ioctl(struct net_device *dev, struct ip_tunnel_parm *p, int cmd)
}
EXPORT_SYMBOL_GPL(ip_tunnel_ioctl);
-int ip_tunnel_change_mtu(struct net_device *dev, int new_mtu)
+int __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;
}
+EXPORT_SYMBOL_GPL(__ip_tunnel_change_mtu);
+
+int ip_tunnel_change_mtu(struct net_device *dev, int new_mtu)
+{
+ return __ip_tunnel_change_mtu(dev, new_mtu, true);
+}
EXPORT_SYMBOL_GPL(ip_tunnel_change_mtu);
static void ip_tunnel_dev_free(struct net_device *dev)
diff --git a/net/openvswitch/vport-vxlan.c b/net/openvswitch/vport-vxlan.c
index 1605691d94144aee0fc50ffb17be05eca2b59675..de9cb19efb6a3e2774624c29b2fe5c977ef92fe4 100644
--- a/net/openvswitch/vport-vxlan.c
+++ b/net/openvswitch/vport-vxlan.c
@@ -91,6 +91,8 @@ static struct vport *vxlan_tnl_create(const struct vport_parms *parms)
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) {