On 6/25/19 2:22 PM, David Ahern wrote:
> On 6/25/19 4:33 AM, Stephen Suryaputra wrote:
>> @@ -363,10 +376,20 @@ int ip_mc_output(struct net *net, struct sock *sk,
>> struct sk_buff *skb)
>> #endif
>> ) {
>> struct sk_buff *newskb = skb_clone(skb, GFP_ATOMIC);
>> - if (newskb)
>> + if (newskb) {
>> + /* Reset rt_iif so that inet_iif() will return
>> + * skb->dev->ifIndex which is the VRF device for
>> + * socket lookup. Setting this to VRF ifindex
>> + * causes ipi_ifindex in in_pktinfo to be
>> + * overwritten, see ipv4_pktinfo_prepare().
>> + */
>> + if (netif_is_l3_slave(dev))
>
> seems like the rt_iif is a problem for recirculated mcast packets in
> general, not just ones tied to a VRF.
>
>> + ip_mc_reset_rt_iif(net, rt, newskb);
>> +
>> NF_HOOK(NFPROTO_IPV4, NF_INET_POST_ROUTING,
>> net, sk, newskb, NULL, newskb->dev,
>> ip_mc_finish_output);
>> + }
>> }
>>
>> /* Multicasts with ttl 0 must not go beyond the host */
Also, wouldn't this problem apply to broadcast packets as well if they
get recirculated back up the stack? Maybe then the reset_rt_iif needs to
be done in ip_mc_finish_output.
