vti6: Add pmtu handling to vti6_xmit. (ccd740cb) · Commits · 戴 / test

We currently rely on the PMTU discovery of xfrm. However if a packet is localy sent, the PMTU mechanism of xfrm tries to to local socket notification what might not work for applications like ping that don't check for this. So add pmtu handling to vti6_xmit to report MTU changes immediately. Signed-off-by:

Steffen Klassert <steffen.klassert@secunet.com> Signed-off-by:

Alexander Duyck <alexander.h.duyck@redhat.com> Signed-off-by:

David S. Miller <davem@davemloft.net>

net/ipv6/ip6_vti.c

+14 −0

Original line number	Diff line number	Diff line
		@@ -435,6 +435,7 @@ vti6_xmit(struct sk_buff skb, struct net_device dev, struct flowi *fl)
		struct net_device *tdev;
		struct xfrm_state *x;
		int err = -1;
		int mtu;

		if (!dst)
		goto tx_err_link_failure;
		@@ -468,6 +469,19 @@ vti6_xmit(struct sk_buff skb, struct net_device dev, struct flowi *fl)
		skb_dst_set(skb, dst);
		skb->dev = skb_dst(skb)->dev;

		mtu = dst_mtu(dst);
		if (!skb->ignore_df && skb->len > mtu) {
		skb_dst(skb)->ops->update_pmtu(dst, NULL, skb, mtu);

		if (skb->protocol == htons(ETH_P_IPV6))
		icmpv6_send(skb, ICMPV6_PKT_TOOBIG, 0, mtu);
		else
		icmp_send(skb, ICMP_DEST_UNREACH, ICMP_FRAG_NEEDED,
		htonl(mtu));

		return -EMSGSIZE;
		}

		err = dst_output(skb);
		if (net_xmit_eval(err) == 0) {
		struct pcpu_sw_netstats *tstats = this_cpu_ptr(dev->tstats);

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