vti6: Don't report path MTU below IPV6_MIN_MTU.

In vti6_xmit(), the check for IPV6_MIN_MTU before we
send a ICMPV6_PKT_TOOBIG message is missing. So we might
report a PMTU below 1280. Fix this by adding the required
check.

Fixes: ccd740cbc6 ("vti6: Add pmtu handling to vti6_xmit.")
Signed-off-by: Steffen Klassert <steffen.klassert@secunet.com>
This commit is contained in:
Steffen Klassert 2017-02-15 11:38:58 +01:00
parent 4c86d77743
commit e3dc847a5f

View File

@ -484,11 +484,15 @@ vti6_xmit(struct sk_buff *skb, struct net_device *dev, struct flowi *fl)
if (!skb->ignore_df && skb->len > mtu) {
skb_dst(skb)->ops->update_pmtu(dst, NULL, skb, mtu);
if (skb->protocol == htons(ETH_P_IPV6))
if (skb->protocol == htons(ETH_P_IPV6)) {
if (mtu < IPV6_MIN_MTU)
mtu = IPV6_MIN_MTU;
icmpv6_send(skb, ICMPV6_PKT_TOOBIG, 0, mtu);
else
} else {
icmp_send(skb, ICMP_DEST_UNREACH, ICMP_FRAG_NEEDED,
htonl(mtu));
}
return -EMSGSIZE;
}