Re: [PATCH net] ipv6: fix cached route reuse for SO_MARK control messages

[Xia Yan]

Hi Willem,

Thanks for the review. I reproduced both on a 6.6-based kernel.

With a connected UDP socket and a cached route, an IPV6_TCLASS cmsg
bypasses a DSCP rule pointing to a prohibit route. Clearing the cache
makes the same send fail with EACCES. The IPv4 case returns EACCES
with or without a cached route.

Under ECMP, changing the per-message flow label keeps using the cached
nexthop. Clearing the cache selects the other nexthop for that label.
Packet captures confirmed the requested traffic class and flow label.

I'll follow up separately for net-next.

Best regards,
Xia