Re: [RFC PATCH 0/3] l3mdev icmp error route lookup fixes

[David Ahern]

On 10/5/20 9:30 AM, David Ahern wrote:
> On 9/25/20 1:04 PM, Mathieu Desnoyers wrote:
>> Hi,
>>
>> Here is an updated series of fixes for ipv4 and ipv6 which which ensure
>> the route lookup is performed on the right routing table in VRF
>> configurations when sending TTL expired icmp errors (useful for
>> traceroute).
>>
>> It includes tests for both ipv4 and ipv6.
>>
>> These fixes address specifically address the code paths involved in
>> sending TTL expired icmp errors. As detailed in the individual commit
>> messages, those fixes do not address similar icmp errors related to
>> network namespaces and unreachable / fragmentation needed messages,
>> which appear to use different code paths.
>>
>> The main changes since the last round are updates to the selftests.
>>
> 
> This looks fine to me. I noticed the IPv6 large packet test case is
> failing; the fib6 tracepoint is showing the loopback as the iif which is
> wrong:
> 
> ping6  8488 [004]   502.015817: fib6:fib6_table_lookup: table 255 oif 0
> iif 1 proto 58 ::/0 -> 2001:db8:16:1::1/0 tos 0 scope 0 flags 0 ==> dev
> lo gw :: err -113
> 
> I will dig into it later this week.
> 

I see the problem here -- source address selection is picking ::1. I do
not have a solution to the problem yet, but its resolution is
independent of the change in this set so I think this one is good to go.