geneve: Relax MTU constraints

[karo-tx-linux.git] / drivers / net / geneve.c

diff --git a/drivers/net/geneve.c b/drivers/net/geneve.c
index c2b79f5d1c89b6b5872c8197fde3eb2d806d4f36..240620c5888a18538e2bb66d6b2bda6d0209fd1b 100644 (file)
--- a/drivers/net/geneve.c
+++ b/drivers/net/geneve.c
@@ -310,15 +310,15 @@ static int geneve_udp_encap_recv(struct sock *sk, struct sk_buff *skb)
 
        /* Need Geneve and inner Ethernet header to be present */
        if (unlikely(!pskb_may_pull(skb, GENEVE_BASE_HLEN)))
-               goto error;
+               goto drop;
 
        /* Return packets with reserved bits set */
        geneveh = geneve_hdr(skb);
        if (unlikely(geneveh->ver != GENEVE_VER))
-               goto error;
+               goto drop;
 
        if (unlikely(geneveh->proto_type != htons(ETH_P_TEB)))
-               goto error;
+               goto drop;
 
        opts_len = geneveh->opt_len * 4;
        if (iptunnel_pull_header(skb, GENEVE_BASE_HLEN + opts_len,
@@ -336,10 +336,6 @@ drop:
        /* Consume bad packet */
        kfree_skb(skb);
        return 0;
-
-error:
-       /* Let the UDP layer deal with the skb */
-       return 1;
 }
 
 static struct socket *geneve_create_sock(struct net *net, bool ipv6,
@@ -998,6 +994,17 @@ 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);
@@ -1042,7 +1049,7 @@ 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,
@@ -1155,7 +1162,7 @@ static int geneve_configure(struct net *net, struct net_device *dev,
        struct geneve_net *gn = net_generic(net, geneve_net_id);
        struct geneve_dev *t, *geneve = netdev_priv(dev);
        bool tun_collect_md, tun_on_same_port;
-       int err;
+       int err, encap_len;
 
        if (!remote)
                return -EINVAL;
@@ -1187,6 +1194,14 @@ static int geneve_configure(struct net *net, struct net_device *dev,
        if (t)
                return -EBUSY;
 
+       /* make enough headroom for basic scenario */
+       encap_len = GENEVE_BASE_HLEN + ETH_HLEN;
+       if (remote->sa.sa_family == AF_INET)
+               encap_len += sizeof(struct iphdr);
+       else
+               encap_len += sizeof(struct ipv6hdr);
+       dev->needed_headroom = encap_len + ETH_HLEN;
+
        if (metadata) {
                if (tun_on_same_port)
                        return -EPERM;