diff --git a/net/ipv6/ip6_vti.c b/net/ipv6/ip6_vti.c index ff3bd863fa03..0224c032dca5 100644 --- a/net/ipv6/ip6_vti.c +++ b/net/ipv6/ip6_vti.c @@ -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);