diff options
| -rw-r--r-- | net/ipv6/ip6_output.c | 13 |
1 files changed, 13 insertions, 0 deletions
diff --git a/net/ipv6/ip6_output.c b/net/ipv6/ip6_output.c index 4cfdad4e835..5a5b7d4ad31 100644 --- a/net/ipv6/ip6_output.c +++ b/net/ipv6/ip6_output.c @@ -567,6 +567,19 @@ static int ip6_fragment(struct sk_buff *skb, int (*output)(struct sk_buff *)) nexthdr = *prevhdr; mtu = dst_mtu(&rt->u.dst); + + /* We must not fragment if the socket is set to force MTU discovery + * or if the skb it not generated by a local socket. (This last + * check should be redundant, but it's free.) + */ + if (!np || np->pmtudisc >= IPV6_PMTUDISC_DO) { + skb->dev = skb->dst->dev; + icmpv6_send(skb, ICMPV6_PKT_TOOBIG, 0, mtu, skb->dev); + IP6_INC_STATS(ip6_dst_idev(skb->dst), IPSTATS_MIB_FRAGFAILS); + kfree_skb(skb); + return -EMSGSIZE; + } + if (np && np->frag_size < mtu) { if (np->frag_size) mtu = np->frag_size; |