Commit c1a800e8 authored by Stefano Brivio's avatar Stefano Brivio Committed by David S. Miller
Browse files

geneve: Support for PMTU discovery on directly bridged links 



If the interface is a bridge or Open vSwitch port, and we can't
forward a packet because it exceeds the local PMTU estimate,
trigger an ICMP or ICMPv6 reply to the sender, using the same
interface to forward it back.

If metadata collection is enabled, set destination and source
addresses for the flow as if we were receiving the packet, so that
Open vSwitch can match the ICMP error against the existing
association.

v2: Use netif_is_any_bridge_port() (David Ahern)

Signed-off-by: default avatarStefano Brivio <sbrivio@redhat.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent fc68c995

drivers/net/geneve.c

+51 −5
Original line number Diff line number Diff line
@@ -893,8 +893,31 @@ static int geneve_xmit_skb(struct sk_buff *skb, struct net_device *dev, 
	if (IS_ERR(rt))

		return PTR_ERR(rt);



	skb_tunnel_check_pmtu(skb, &rt->dst,

			      GENEVE_IPV4_HLEN + info->options_len, false);

	err = skb_tunnel_check_pmtu(skb, &rt->dst,

				    GENEVE_IPV4_HLEN + info->options_len,

				    netif_is_any_bridge_port(dev));

	if (err < 0) {

		dst_release(&rt->dst);

		return err;

	} else if (err) {

		struct ip_tunnel_info *info;



		info = skb_tunnel_info(skb);

		if (info) {

			info->key.u.ipv4.dst = fl4.saddr;

			info->key.u.ipv4.src = fl4.daddr;

		}



		if (!pskb_may_pull(skb, ETH_HLEN)) {

			dst_release(&rt->dst);

			return -EINVAL;

		}



		skb->protocol = eth_type_trans(skb, geneve->dev);

		netif_rx(skb);

		dst_release(&rt->dst);

		return -EMSGSIZE;

	}



	sport = udp_flow_src_port(geneve->net, skb, 1, USHRT_MAX, true);

	if (geneve->cfg.collect_md) {
@@ -955,8 +978,30 @@ static int geneve6_xmit_skb(struct sk_buff *skb, struct net_device *dev, 
	if (IS_ERR(dst))

		return PTR_ERR(dst);



	skb_tunnel_check_pmtu(skb, dst, GENEVE_IPV6_HLEN + info->options_len,

			      false);

	err = skb_tunnel_check_pmtu(skb, dst,

				    GENEVE_IPV6_HLEN + info->options_len,

				    netif_is_any_bridge_port(dev));

	if (err < 0) {

		dst_release(dst);

		return err;

	} else if (err) {

		struct ip_tunnel_info *info = skb_tunnel_info(skb);



		if (info) {

			info->key.u.ipv6.dst = fl6.saddr;

			info->key.u.ipv6.src = fl6.daddr;

		}



		if (!pskb_may_pull(skb, ETH_HLEN)) {

			dst_release(dst);

			return -EINVAL;

		}



		skb->protocol = eth_type_trans(skb, geneve->dev);

		netif_rx(skb);

		dst_release(dst);

		return -EMSGSIZE;

	}



	sport = udp_flow_src_port(geneve->net, skb, 1, USHRT_MAX, true);

	if (geneve->cfg.collect_md) {
@@ -1013,6 +1058,7 @@ static netdev_tx_t geneve_xmit(struct sk_buff *skb, struct net_device *dev) 
	if (likely(!err))

		return NETDEV_TX_OK;



	if (err != -EMSGSIZE)

		dev_kfree_skb(skb);



	if (err == -ELOOP)

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