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Commit d41bb33b authored by Xin Long's avatar Xin Long Committed by David S. Miller
Browse files

ip6_tunnel: update mtu properly for ARPHRD_ETHER tunnel device in tx path 



Now when updating mtu in tx path, it doesn't consider ARPHRD_ETHER tunnel
device, like ip6gre_tap tunnel, for which it should also subtract ether
header to get the correct mtu.

Signed-off-by: default avatarXin Long <lucien.xin@gmail.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent 2d40557c

net/ipv6/ip6_tunnel.c

+3 −2
Original line number Diff line number Diff line
@@ -1043,6 +1043,7 @@ int ip6_tnl_xmit(struct sk_buff *skb, struct net_device *dev, __u8 dsfield, 
	struct dst_entry *dst = NULL, *ndst = NULL;

	struct net_device *tdev;

	int mtu;

	unsigned int eth_hlen = t->dev->type == ARPHRD_ETHER ? ETH_HLEN : 0;

	unsigned int psh_hlen = sizeof(struct ipv6hdr) + t->encap_hlen;

	unsigned int max_headroom = psh_hlen;

	bool use_cache = false;
@@ -1124,7 +1125,7 @@ int ip6_tnl_xmit(struct sk_buff *skb, struct net_device *dev, __u8 dsfield, 
				     t->parms.name);

		goto tx_err_dst_release;

	}

	mtu = dst_mtu(dst) - psh_hlen - t->tun_hlen;

	mtu = dst_mtu(dst) - eth_hlen - psh_hlen - t->tun_hlen;

	if (encap_limit >= 0) {

		max_headroom += 8;

		mtu -= 8;
@@ -1133,7 +1134,7 @@ int ip6_tnl_xmit(struct sk_buff *skb, struct net_device *dev, __u8 dsfield, 
		mtu = IPV6_MIN_MTU;

	if (skb_dst(skb) && !t->parms.collect_md)

		skb_dst(skb)->ops->update_pmtu(skb_dst(skb), NULL, skb, mtu);

	if (skb->len - t->tun_hlen > mtu && !skb_is_gso(skb)) {

	if (skb->len - t->tun_hlen - eth_hlen > mtu && !skb_is_gso(skb)) {

		*pmtu = mtu;

		err = -EMSGSIZE;

		goto tx_err_dst_release;